2000 Saturn LS Code P0050. Vehicle has no drivability issues. Code related to O2 Sensor circuit. Vehicle has 4 02 Sensors What should I check and replace.

code p0050 refers to heated oxygen sensor (HO2S) 1 bank 2 heater control ---circuit malfunction===causes --wiring---HO2S ---ECM
replace the sensor in the exhaust pipe and the code should clear

02 sensor circuit low voltage ---answer is copied from obd-codes .com you can visit this site for more information if necessary Usually rear o2 sensor problems won't cause drivability issues since they are an input that measures catalyst efficiency (unlike front o2 sensors). However if you have other codes present, like lean codes or pre-o2 sensor codes, then they may cause drivability problems as well as P0143. The following symptoms may be present: MIL (Malfunction Indicator Lamp) illumination Engine performance issues Engine running rough Engine running rich (only if PCM is trying to add fuel to compensate for low o2 sensor voltage reading) Engine running lean (only if vacuum leak is large enough that PCM can't compensate by adding fuel) Poor idle Causes If you have reason to believe that your engine is running lean, fix that problem first, then clear codes and see if the P0157 code resets. An engine that is running lean could set this code, but usually there will be lean codes (P0171, P0174) present. The following could be causes: Air leaks in exhaust in front of o2 sensor giving false reading Engine running excessively lean O2 sensor connector damaged/corroded O2 sensor signal circuit is shorted to ground O2 sensor ground circuit is open O2 sensor has failed (it may be contaminated with fuel or coolant) PCM has failed

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Below is a picture of the location of both O2 sensors for your vehicle. Also the last picture is your evap. system. In the "dotted lined" area I would check for rotten or lose hoses in that area as well the vapor pressure sensor could be faulty as well. Hope this helps.

Heater control circuit is your O2/oxygen sensor which controls your emissions and keeps the car running efficiently. They go out quite frequently and need to be replaced. Wont cause any drivability issues other then lower fuel economy and check engine light. Sensors run between $50-$200 each.

if you have an O2 sensor faliure you will have a code for it. in fact youe exterra doesnt have O2 sensors. it has A/F sensor or "air/fuel sensor" if it went bad, than you will have a code for that sensor. What is the code number that you have?? need to start there.

Appears it is an Oxygen sensor error, they are located in the exhaust system, in the v6, that code indicates the second bank (but unsure which bank that is) Ideally you need to take the car in for service, or at least inspect the Oxygen sensors, the code indicates that teh heater element has failed.

This code means:

P0160 - O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)

In most cases the sensor is bad and needs to be replaced. I would try this first since it's the cheapest and easiest route.

If your O2 sensors are malfunctioning, the main symptom would be that the Check Engine light will come on. On some vehicles, an O2 sensor circuit shorted to ground can cause a no-start problem.
If the "Check Engine" or "Service Engine Soon" light is on and there is a code for the O2 sensors, I would like to also advise you that many O2 sensor codes are not caused by the O2 sensors themselves. In many cases, the O2 sensors are only REPORTING the problem. for example, a code P0171 "Oxygen Sensor Lean" code is rarely ever caused by the O2 sensor. It is usually caused by a vacuum leak or a failed Mass Airflow sensor (MAF) or Manifold Absolute Pressure sensor (MAP) or a bad fuel injector. In these cases, repairing the real reason that the engine is running lean will fix the O2 Sensor code without replacing the O2 sensor.

is this a 4 or 6 cylinder?
if a 4 cylinder it will only have 2 o2 sensors
V6 will have 4 o2 senors which the sensor will be the right side of the engine first sensor.
1st sensor on exhaust, I recommend if you change one change all, as this will make the computer when it rechecks the system you have all clean/fast responding sensors.

if you have a slow response it means the sensor is dirty and not reading well, which is usually caused by minor misfires that the engine computer dismisses, so a tune up would be recommended too.

This would be on of your downstream heated Oxygen sensors. I believe you have 3 - 4 O2 sensors on this vehicle. Would recommend taking to a repair shop for the repairs, some of these O2 sensors can be tricky to get to. Hope this helps