Check engine light on with two codes P01131 and P0135. I change the o2 sensor in bank 1 sensor 1 and that has not helped. Dont know what to do. Any suggestions on what to do??

SOURCE: P0155 & P0135

O2 sensors are tricky. sometimes like anything else they fail. many times though the exhaust mixture they encounter is out of their range and that shows up as a failure.since you seem to have no other problems , I would go ahead and change them, but don't be disappointed if the code shows up again (at least you know it's not the sensors.) I don't like using the process of elimination when doing repairs but sometimes you must.

juggernautxt

• 145 Answers
• Posted on May 06, 2009

SOURCE: Code: P0133 - O2 Sensor Circuit Slow Response Bank 1 Sensor 1

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.

SOURCE: 2004 Sequoia. VSC TRAC, TRAC OFF, and Check

It is not hard to change the sensor, it just screws into a threaded hole. The light will not go out immeditaly, after the sensor is replaced. It needs to go thru a drive cycle. Your best bet is to replace the sensor and get the code cleard by whoever scanned it for the 0031 code.

SOURCE: Where is bank1 sensor 1 (O2 sensor) of 2003 Mitsubishi Eclipse

if its a 4 cylinder it will the 02 sensor closest or if not in the exhaust manifold

SOURCE: OBD II code P0133 (O2 bank 1 sensor 1) which

It is the front sensor, if your car is the type that has 2 front sensors it will be the one closest to the timing chain / belt (left hand side of engine)