Measure the voltage on the (K141) O2 Sensor 1/2 Signal circuit in the O2 Sensor harness connector. This told me that the wiring problem was in between the strut tower plug and the sensor plug. Pass through this lovely $1. It doesn't hurt if the total voltage goes above 1. 9V) there is an excess of fuel in the mixture. good morning everyone. the rear o2 sensor makes sure that your cat is still doing it job of burning any on burn gas. P0135-O2 sensor heater circuit malfunction (Bank no. Is the voltage above 0 volts? Yes. 500v is considered stoichmetric (the proper amount of fuel). I recently fixed two broken exhaust manifold studs on the passenger side, and I was hoping that would clear up my issue, but it doesn't seem to have helped. The oxygen, or O2, sensor reads the percentage of oxygen in the exhaust coming from the engine and sends this information to the computer. 3L F23A1 F23A5 | eBay. 21 Downstream Heated Oxygen Sensor Voltage Grounded. The O2 Sensor voltage should read 5. What is the most important emissions control device on a vehicle today? The catalytic converter, because it cleans up any exhaust pollutants that exit the engine. The sensor's voltage reading should also be fairly steady (not changing up or down), and average 0. 2 volts (lean) to 1. In most cases, a properly operating upstream O2 sensor should rapidly switch between 0. If OK so far, remove the flame. I'm getting an intermittent P013C code for passenger side downstream O2 sensor slow to respond rich-lean. The catalytic converter works to maintain the stoichiometric air-fuel ratio 14. The sensor's voltage reading should also be fairly steady (not changing up or down), and average 0. HOWEVER, the downstream, although new, did endure a lot of coolant when the motor blew. 0 Sensor Silverado 2004 Gas for 2 Chevy Chevy Gas 2 for Oxygen Sensor Silverado 6. P1621-O2 SENSOR REFERENCE VOLTAGE CIRCUIT LOW Theory of Operation Normally, the O2 Sensor signal voltage will fluctuate between 0. 27 volts, than starts to vary mainly - Answered by a verified Auto Mechanic. An oxygen sensor (O2 sensor) measures the amount of oxygen in the exhaust gases, sending the signal to the engine computer. 7:1, gives a reading of around 0. 2pcs O2 Oxygen Sensor Up Downstream For 1998-2002 Honda Accord 2. Tried new computer and still no sensor voltage. I have a code P0420 in my '04 Civic Si. Still has a slight miss but no SES light. In probably 15 seconds, the sensor gets hot enough to produce a little voltage of it's own and the diagnostic bias disappears. The voltage produced by the sensor is nonlinear with respect to oxygen concentration. O2 sensor Bias voltages The computer will send a small bias voltage to the O2 it will be a very weak voltage as it will pass through a resistor inside the computer to drop is current. With the scan tool, monitor the 1/2 O2 Sensor voltage. It has original O2 sensors and catalytic converters. O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2) What the P0137 code means. The Powertrain Control Module (PCM) is not able to calculate a negative voltage from the O2 Sensors. The the upstream sensor moved from 0. The downstream O2 has only one job, that is to monitor the catalytic converter. 45 volts or so. Includes 4-20 mA Output, 3 Onboard Relays, Modbus RS-485 Communication and LCD Digital Display. 2 volts indicates a lean mixture and 0. "O2 Oxygen Sensor Circuit High Voltage (Bank1, Sensor2)" Checked the sensor, it was indeed high-ish 0. Buy O2 Oxygen Sensor - AM-26912137 now at AM-AutoParts! Always Free Shipping. Downstream O2 sensors work? 2002 Dodge Dakota, 3. The downstream O2 sensor voltage is pretty steady, but usually below 0. The O2 Sensor voltage should read 5. (or O2 sensor 1) is. In the example below, the downstream sensor voltage uses almost the whole 0-1 Volt range during a test drive. Some inline 6 cylinder engines have Bank 1 as Cylinders 1-3 and Bank 2 as Cylinders 4-6. Upstream sensors actually control the air to fuel ratio, downstream sensors only purpose is to check catalyst performance (used to check effeciency of the catalytic convertor) if the converter fails or is removed both upstream and downstream will. This tells you that the O2 sensor is working and NOT defective. 0 volts to 2. Got the car in with about 95k miles. Still has a slight miss but no SES light. 11 v; sensor 2, 0. The O2 voltage will be exactly 450. You guys have the o2 sensor backwards. 7L GM vehicle is not that hard to do. What would cause downstream o2 sensor voltage to be low, other than o2 sensor itself is bad? I understand that if the upstream o2 sensor voltage is high or low, it could possibly mean that the o2 sensor itself is good and the combustion got a problem. The downstream sensor has the same voltage as the other sensor before I start the truck, but once I start the truck the sensor loses most of its voltage within a minute or so. 6V within 20 seconds, if not, the most likely cause is an internal open circuit or lead fouling. Set Condition: The oxygen sensor signal voltage is below 2. As fuel quantity decreases we return to a lean mixture, and sensor voltage drops. By narrowing the scope of the data stream to include only pertinent data, you will get a faster data response. First sensor is measuring it right after gases escape engine and this data is used to adjust fuel trim of the engine, as well as catch some faulty conditions. Standing facing the Flywheel end of the engine, Bank 1 is located on the right hand side of the engine, there are two sensors one upstream, on the engine side of the catalytic converter, and one down stream on the exhaust side of the catalytic converter. Chevrolet Silverado 1999-2006: How to Replace Oxygen (O2) Sensors. If the converter is doing its job and is reducing the pollutants in the exhaust, the downstream oxygen sensor should show little activity (few lean-to-rich transitions, which are also called "crosscounts"). Start the engine. You guys have the o2 sensor backwards. if you google search "nissan code p0430" you will find all the info. The the upstream sensor moved from 0. Some inline 6 cylinder engines have Bank 1 as Cylinders 1-3 and Bank 2 as Cylinders 4-6. The downstream O2 has only one job, that is to monitor the catalytic converter. The sensor can be tested for output by connecting to it a digital voltmeter, set to a 2v scale. 45 volts is recognized by the PCM as a rich exhaust; below 0. With the engine running, Sensor 1 wide range reading is running between 3. 8 volts but jumping around somewhat while driving. The post-catalyst sensor does not suffer this problem because most of the excess fuel and oxygen is consumed in the catalyst. From what I can tell you can run with downstream O2 always at 0. Typical lean voltage readings are between 0 and. Repair the short to battery voltage in the (K141) O2 Sensor 1/2 Signal circuit. With the engine idling, the sensor voltage should be cycling from low voltage to high voltage. Check Base Engine Idle, EGR, Fuel System and Air Induction System. I'm working with a Autel Maxidas system. We changed the spark plugs and reset the check engine light but it again came back on. Bank 2 upstream and downstream O2 sensors operating normally. 4v with no oscillation The downstream sensor was reading a pretty steady 0. As you know, a catalytic converter is a major part of the vehicle's emission control system. Compatible sensor types include electrochemical and catalytic bead options to provide monitoring solutions for a wide variety of toxic and combustible gas applications. Oxygen O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2) What does that mean? This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Reduced output voltage. The rate of change that the O2 sensor detects is called the big slope. I recently fixed two broken exhaust manifold studs on the passenger side, and I was hoping that would clear up my issue, but it doesn't seem to have helped. If the signal from the downstream oxygen sensor starts to mirror that from the upstream oxygen sensor(s), it means converter efficiency has dropped off and the converter isn't cleaning up the pollutants in the exhaust. Therefore, the downstream oxygen sensor (sensor 2) should produce a steady voltage of approximately 0. When diagnosing this DTC, only diagnose the O2 Sensor that set the DTC. The sensor's voltage reading should also be fairly steady (not changing up or down), and average 0. Making the fuel mixture artificially rich by feeding propane into the intake manifold should cause the sensor to respond almost immediately (within 100 milliseconds) and go to maximum (0. right side from driver seat POV) for "High Voltage error" or something along those lines. And shimming is done for rear o2 sensor. Discover clearance sale on Fi Right - we carry wide range of Fi Right. I don't see any issues with exhaust system. Either the sensor failed and isn’t producing voltage or there’s a problem in the wiring harness that supplies power, ground and returns reference signals to the electronic control module. P0132 | O2 Sensor Circuit High Voltage Bank 1 Sensor 1 | The front heated oxygen sensor (or O2 sensor 1) is placed into the exhaust manifold. Repair Information for P0137 code. A "cold" engine makes the computer change the fuel air ratio so the output voltage of the o2 sensor switches between about 100 and 850/900 mV and after a while the sensor may output a switch voltage between about 200 and 700/750 mV, for turbocharged cars even less. Measure the voltage on the (K141) O2 Sensor 1/2 Signal circuit in the O2 Sensor harness connector. First sensor is measuring it right after gases escape engine and this data is used to adjust fuel trim of the engine, as well as catch some faulty conditions. 662 on three different dates. Basically, the PCM is looking for a steady reading of about. The converter now starts to clean the exhaust and remove the pollutants. I am going to look into this a little more for you and see what I can dig up. The time taken for the voltage to change from 0. If any of the tests fail, then the upstream O2 Sensor should be replaced. If it does, then the catalytic converter is bad and needs to be replaced. 3 volts and rich readings range from. My LTFT is always at 0. Of course, this made the original 555 design obsolete, so the output of the 555 was changed to pulse from 0-1 volt at a fixed or even adjustable rate, this is the most current use of the 555 that we. P0136 "O2 Sensor Circuit Malfunction (Sensor 2). With the engine running, the O2 sensor signals are viewed in graphing mode on the scan tool. The Powertrain Control Module monitors the downstream O2 sensor feedback control, called downstream fuel trim, to detect any shift in the upstream O2 sensor target voltage from nominal target voltage. The DTC must be retrieved using a scanning tool. Therefore, the downstream oxygen sensor (sensor 2) should produce a steady voltage of approximately 0. Is you check engine light on because of a bad oxygen sensor? You don't have to spend your life savings to replace a defective O2 sensor. when i hook up the code reader it says something about high voltage something or other (sorry, don't have the code reader with me, and my memory is worthless). The signal will however not flip-flop from 0. 9 volts or more when heated, show 0. This continuous feedback loop is the heart of the fuel control system. The downstream O2 Sensor is located in the exhaust path behind the catalytic converter, is monitored for proper response to assure optimum catalytic converter efficiency. 78 once the engine is warm it moves slowly as I accelerate, but never oscillates up and. Checked wiring and everything looks good. The catalytic converter needs to be replaced, but I would like to try to fool the downstream O2 sensor instead. I have checked the downstream O2 sensor and i am 100% sure its working good, as i put it in a friends car (same as mine) and it was reading 0. When the fuel mixture is rich (less oxygen in the exhaust), the sensor's output jumps up to a high of about 0. Many newer vehicles use an O2 sensor that uses a wider voltage range of 2. HOWEVER, the downstream, although new, did endure a lot of coolant when the motor blew. The voltage will drop a bit at idle and raise a little when running but should always be stable and not varying like the front sensor. It changes a tiny bit. The sensor's voltage reading should also be fairly steady (not changing up or down), and average 0. - 30 Day Warranty]. The voltage range, in most cases, varies between 0. Once the converter lights off, the downstream O2 sensor will settle down and “flat-line” at a steady voltage reading usually around 0. Its voltage depends on the amount of oxygen in the exhaust stream. I don't see any issues with exhaust system. 25 is the more normal setting for downstream sensors. However, you can clearly see that the average cruise value is about 600 mV, indicating that this converter is oxidizing. For this test you will need a. 0 Volt fluctuating voltage range. O2 sensor Bias voltages The computer will send a small bias voltage to the O2 it will be a very weak voltage as it will pass through a resistor inside the computer to drop is current. With the scan tool, monitor the 1/2 O2 Sensor voltage. The O2 Sensor voltage should read 5. Anyone ever seen this issue on a bluetec?. No control unit fault codes are displayed. Oxygen 1 Sensor 4xUp+Downstream 2500HD 6. 1) P0137-Left bank downstream or downstream and pre-catalyst O2 sensor voltage shorted to ground P0138-Left bank downstream or downstream and pre-catalyst O2 sensor shorted to voltage P0141-Downstream, left bank downstream or pre-catalyst O2 sensor heater failure P0152-Left. The data from this sensor is compared to that of the upstream sensor. 2002 tacoma 2. 5 volts or higher. Order today by 4 P. If the voltage is low (approx. 1 volts (lean) to 0. 1-volt and 0. I'm about to take my truck to the shop tomorrow and dump 60$ for them to remove this O2 sensor. The 2005 Nissan shop manual ONLY shows a A/F sensor for the pre cat sensor and a O2 sensor for the post cat sensor. The signal will however not flip-flop from 0. The voltage produced by the sensor is nonlinear with respect to oxygen concentration. How to Check Honda Oxygen Sensors. ,HEATED SENSOR - DOWNSTREAM REAR - 2 DR - 4 DR [Wholesaler Closeout - Private Label Pkg. Manfucturers call this crossing of the 0. I'm getting an intermittent P013C code for passenger side downstream O2 sensor slow to respond rich-lean. As far as CAT temps, no, the scanner has no selectable entry for anythign related to the CAT. The voltage range, in most cases, varies between 0. Stable, accurate readings because a 5 wire, truly wide band oxygen sensor is used. I'm not sure where to go from here. I already replaced the bank 2 cat with the used one I had purchased, due to lack of power under load, the downstream o2 sensor was almost identical to the upstream, and the CEL for P0430. - 30 Day Warranty]. Bank 1 sensor 1 is the primary O2 sensor that should be located on the header. Sometimes called an "executive car", the S80 was and continues to be Volvo's top-of-the-line passenger car. Do not replace just one sensor replace them in pairs only. The best way to look at an o2 sensor is with a digital storage oscilloscope and look at a wave form. 0, actually stopped monitering it for a while because i didnt think it was giving me any data. Set Condition: The oxygen sensor signal voltage is below 2. 1V (downstream is 0. I have found the TaN / WHite sensor wire where it goes into the PCM. Some inline 6 cylinder engines have Bank 1 as Cylinders 1-3 and Bank 2 as Cylinders 4-6. I got a P0420 code on my Altima so I began looking at my O2 sensors with a diagnostic tool that showed me the waveforms and voltages. - 30 Day Warranty]. 4v with no oscillation The downstream sensor was reading a pretty steady 0. Sensor 1 represents the “upstream” A/F sensors in the exhaust manifold. 45 volt mark O2 cross counts. 100 Volts and 0. However, you can clearly see that the average cruise value is about 600 mV, indicating that this converter is oxidizing. Scanner shows voltage swinging between one and eight tenths of a volt rather than a steady. With the engine idling, the sensor voltage should be cycling from low voltage to high voltage. 8 Volt: Payment Shipping Returns Contact Us. when i hook up the code reader it says something about high voltage something or other (sorry, don't have the code reader with me, and my memory is worthless). Step by step instructions on how to change the Oxygen O2 Sensor in your car. An air/fuel ratio of 14. 5 Volts DC and this is what your looking for (in a normally operating catalytic converter, the rear O2 sensor should report a steady voltage between 0. Dealer wants over $300 to replace and says if the sensor is not replaced, damage will occur to catalytic converters. ,HEATED SENSOR - DOWNSTREAM REAR - 2 DR - 4 DR [Wholesaler Closeout - Private Label Pkg. 45 volt rich/lean switch point for optimum fuel efficiency and emissions. The voltage produced by the sensor is nonlinear with respect to oxygen concentration. ² Set Condition: The oxygen sensor signal voltage is below 1. 45 volts is interpreted by the ECM as a rich exhaust, and an O2 sensor voltage signal below 0. 4L with manual transmission) was throwing codes of a bad O2 sensor heater on the upstream sensor. A downstream O2 will not oscillate rapidly. 035 or so volts but nothing compared to the same sensor on bank 1 which is. Scanner shows voltage swinging between one and eight tenths of a volt rather than a steady. Checked wiring and everything looks good. 3L F23A1 F23A5 | eBay. Magnum EZ CEL Fix Oxygen sensor simulator is available to all cars, trucks and SUV's fitted with 1 up to 4-wire narrowband zirconia exhaust gas oxygen sensors working in the standard 0 up to 1. code p0420 has appeared. If the remaining oxygen content is less than 3 % (rich mixture), the sensor voltage rises to 0. ) For a good sensor, voltage should fluctuate constantly between 0. 45 volts or higher. The upsteam sensor was reading a pretty steady 0. 4Pack Oxygen O2 Sensor Up/Downstream for Ford Lincoln Town Car 3. 8 volts, so its doing its job. i replaced the sensor, but it keeps happening. It will just react slower. Since this is a wideband A/F sensor, I do expect voltage above 1V. 4v with no oscillation The downstream sensor was reading a pretty steady 0. An oxygen sensor (O2 sensor) measures the amount of oxygen in the exhaust gases, sending the signal to the engine computer. 5 V, and a lean mixture will cause a low voltage output, around 0. 9V and then go back. Browse sensor chevrolet available to buy today. code p0420 has appeared. It will read an accurate mixture, usually, but not necessarily, a voltage of 0. The sensor voltage should cycle or fluctuate within the 100 mV-900 mV (0. Oxygen O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2) What does that mean? This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Bank 2 upstream and downstream O2 sensors operating normally. This product is small size, easy to. My concern is the downstream O2. downsream o2 sensor 0. The post-catalyst sensor does not suffer this problem because most of the excess fuel and oxygen is consumed in the catalyst. I'll take care of the MAF sensor and get the 2nd 02 sensor voltage up today and re-test, keeping an eye on the LTFT. OK, the heating circuit has failed on my downstream O2 sensor(CEL code P0141). It will just react slower. A good oxygen sensor should produce an oscillating waveform making voltage transitions from near minimum to near maximum. Newer vehicles will have accurate air fuel sensor voltages. 3L New at the best online prices at eBay!. What is O2 sensor simulator? The OBD-II cars (1996-1998) have the two O2 sensors to measure the amount of oxygen in the exhaust gas. 035 or so volts but nothing compared to the same sensor on bank 1 which is. when i hook up the code reader it says something about high voltage something or other (sorry, don't have the code reader with me, and my memory is worthless). Since the introduction of OBDII with both upstream and downstream O2 sensors, the downstream O2 sensor has been used to evaluate catalytic converter operation and to control converter efficiency. Oxygen 1 Sensor 4xUp+Downstream 2500HD 6. 2007 Jeep Grand Cherokee 5. ) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a. im/avd0s The O2 sensors will NOT cause a "No Start" condition (They aren't even looked at by the PCM untill the engine is running) When was the last time your timing belt was replaced, this is usually the conditions when it would fail (Or at start up) Remove the oil cap and have assistant crank the engine while you look to see if the. Upstream sensors actually control the air to fuel ratio, downstream sensors only purpose is to check catalyst performance (used to check effeciency of the catalytic convertor) if the converter fails or is removed both upstream and downstream will. A front oxygen sensor is installed in the exhaust manifold or in the front exhaust pipe before the catalytic converter. O2 sensor Bias voltages The computer will send a small bias voltage to the O2 it will be a very weak voltage as it will pass through a resistor inside the computer to drop is current. To verify the wiring, I plugged the B1S2 harness into the B2S2 o2 sensor and it worked plugged into the other side of the car. If the O2 sensor is a traditional zirconia type sensor, the voltage output drops to about 0. (Use back probe method, DO NOT pierce the wire. The O2 sensor monitors the amount of unburned oxygen in the exhaust and produces a voltage signal that varies from about 0. 45 volts or so. 4L with manual transmission) was throwing codes of a bad O2 sensor heater on the upstream sensor. The sensor voltage should cycle or fluctuate within the 100 mV-900 mV (0. Stable, accurate readings because a 5 wire, truly wide band oxygen sensor is used. Set Condition: No sensor output is received when the PCM powers up the sensor heater. On rare occasions, the signal voltage can drop below 0. P013A-O2 SENSOR 1/2 SLOW RESPONSE - RICH TO LEAN. Order today by 4 P. As you know, a catalytic converter is a major part of the vehicle's emission control system. Is the voltage above 0 volts? Yes. 81 Volts reading from the downstream sensor. When the car got turned off it took minutes for the voltage to drop to 0 so I figured that changing a sensor on a 10 year old car isn't that crazy. However, you can clearly see that the average cruise value is about 600 mV, indicating that this converter is oxidizing. 1) P0137-Left bank downstream or downstream and pre-catalyst O2 sensor voltage shorted to ground P0138-Left bank downstream or downstream and pre-catalyst O2 sensor shorted to voltage P0141-Downstream, left bank downstream or pre-catalyst O2 sensor heater failure P0152-Left. they arent cheap and you can do yourself but depending on age and condition of exhaust can. I don't see any issues with exhaust system. See the max at the red marker in the screen shot below. So is my O2 sensor bad (too low - rich fuel/low O2)? Why I am asking. A "cold" engine makes the computer change the fuel air ratio so the output voltage of the o2 sensor switches between about 100 and 850/900 mV and after a while the sensor may output a switch voltage between about 200 and 700/750 mV, for turbocharged cars even less. Is you check engine light on because of a bad oxygen sensor? You don’t have to spend your life savings to replace a defective O2 sensor. 6 volts and behaving as it should, not bouncing around. High sensor. Making the fuel mixture artificially rich by feeding propane into the intake manifold should cause the sensor to respond almost immediately (within 100 milliseconds) and go to maximum (0. 1 volts or less within one second of flame removal, AND pass the two minute heat test is good regardless of age. As the cat degrades, the voltages starts to fluctuate and mirror that of the up stream sensor switching between rich and lean. Turn the ignition off, disconnect the O2 sensor harness connector. This tells you that the O2 sensor is working and NOT defective. Ram Upstream Oxygen Sensor Goal Voltage From Star Center News #5, February 2000 - tests for those who have access to OBD II or OBD III code readers. Ever after the motor was replaced I was told the car smoked for a good hour before the coolant cleared out of the system. Still has a slight miss but no SES light. Buy heated Oxygen O2 Sensor Rear Downstream sensor 2 for Buick Cadillac Chevrolet GMC Oldsmobile Pontiac compatible with Bosch 13474: Oxygen - Amazon. I have a code P0420 in my '04 Civic Si. I will check what you told me to check. Dealer wants over $300 to replace and says if the sensor is not replaced, damage will occur to catalytic converters. Excess oxygen in the form of regular ambient air will send the O2 sensor voltage signal low (under 0. The upstream O2 sensor was replaced right after the rebuild by the guys who did it, and the downstream O2 sensor is also fairly new. The sensor is most sensitive near the stoichiometric point (where λ = 1) and less sensitive when either very lean or very rich. Backprobe the connector near the O2 sensor to connect the voltmeter to the sensor signal wire. The purpose of this thread is to discuss the modification of the O2 sensor by using spark plug non-foulers as spacers to bring the o2 sensor probe away from the exhaust gases. A good O2 sensor should produce an oscillating waveform at idle that makes voltage transitions from near minimum (0. NOTE: Measure the voltage in reference to ground, not the (K904) O2 Return Downstream circuit. NOTE: The voltage should drop from 5. the dealer is right it can damage your cat but most likly not, but if it the check engine light flashes you need to turn off the car and bring it to the shop becuse that means that it could damage tha cat. Sometimes the sensor with show 0. The downstream O2 Sensor is located in the exhaust path behind the catalytic converter, is monitored for proper response to assure optimum catalytic converter efficiency. Classic symptoms of a done for cat. They're putting out 0. When the fuel mixture is rich (less oxygen in the exhaust), the sensor's output jumps up to a high of about 0. This is because OBD II standards require O2 sensor PID voltage to be displayed in a range between zero and 1 volt. 9L V6, 109K Miles Downstream O2 Sensor questions 32:17. Is the voltage above 0 volts? Yes. Warranty: 5 year unlimited miles. 9 but not up to 1. Don't thgink a resistor is the way--you want something regulated. First O2 Sensor Basics video:. The downstream O2 sensor voltage is pretty steady, but usually below 0. Showcasing our huge array of Turbo 2002 Town Country available for buying right now on the internet. Rather, the O2 sensor is correcting lean due to an overly rich air/fuel ratio. P0137 code definition. The voltage produced by the sensor is nonlinear with respect to oxygen concentration. It can be mounted anywhere close to the throttle body. 100 Volts and 0. An air/fuel ratio of 14. In most cases, a properly operating upstream O2 sensor should rapidly switch between 0. If the converter is doing its job and is reducing the pollutants in the exhaust, the downstream oxygen sensor should show little activity (few lean-to-rich transitions, which are also called "crosscounts"). Therefore, the downstream oxygen sensor (sensor 2) should produce a steady voltage of approximately 0. If any of the tests fail, then the upstream O2 Sensor should be replaced. Because on an O2 sensor rich = high voltage and lean = low voltage. I have a 1g Talon TSi AWD and just got it running and hooked up the data logger and noticed that the o2 sensor just stays at 0 volts and all the fuel trims(L/M/H) are all 100% at idle and driving. 9 volts (rich). The time taken for the voltage to change from 0. 0 Volt fluctuating voltage range. NOTE: The voltage should drop from 5. 5 V, and a lean mixture will cause a low voltage output, around 0. 9 volts or more when heated, show 0. When the car got turned off it took minutes for the voltage to drop to 0 so I figured that changing a sensor on a 10 year old car isn't that crazy. The downstream O2 sensor data should reach a mid-line and settle there, if the engine is running efficiently. Checked wiring and everything looks good. 0 volts to 2. I'd also like to ask, according to the code displayed, the car is running too lean. I was running my scanner to check the volts for each sensor to make sure everything was kosher, but it doesn't seem to be. There are nine sensor tests available on OBDII vehicles. The oxygen sensor upstream of the catalytic converter will normally be referred to as Bank 2 O2 Sensor 1 (B2O2S1) and the downstream oxygen sensor will be Bank 2 O2 Sensor 2 (B2O2S2). Downstream O2 Sensor Voltage. 445 v with ignition on and initial start of vehicle. I am in the process of diagnosing a P0420 (that repeatedly came back after erasures) on my 2000 Corolla. downstream sensor output is alternating voltage from near 0V up to 1V based on readings where generally below 0. US Army, Marines, War Collectibles. If the voltage is high (approx. The freeze frame data collected from a 2008 Nissan Sentra is showing that the O2 sensor voltage (bank 1, sensor 1) is higher than possible.