Fault code #1 bank, #2 oxygen sensor heater.

MLCOOPER

MEMBER
2004 MITSUBISHI ENDEAVOR
6 CYL
2WD
AUTOMATIC
130,000 MILES

I have replaced all 4 oxygen sensors and still have the same fault code. I can reset the computer and light will go off. Start the car and run it a few minutes and turn it off, the check engine light comes back on next time the ignition is turned on with the same fault code, #1 bank, #2 oxygen sensor. Any ideas?

4 Replies

HMAC300

MECHANIC
48,601 POSTS

Check for an air leak and if code is 420 or 430 it's aconverter not O2 sensor. Could be short in wiring as well

Was this

answer

helpful?

Yes

No

-1

Sunday, February 16th, 2014 AT 10:36 AM

HOMER1967

MECHANIC
875 POSTS

Are there any exhaust leaks near that 02? Or even before it. And exactly what code are you getting? Please post the code up here for us to see.

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

-1

Sunday, February 16th, 2014 AT 11:32 AM

MLCOOPER

MEMBER
2 POSTS

Fault code is P0141, #1 bank, #2 oxygen sensor heater.

Was this

answer

helpful?

Yes

No

-1

Sunday, February 16th, 2014 AT 11:39 AM

HOMER1967

MECHANIC
875 POSTS

At this point I would say you need to take it to a shop to have it diagnosed, you have to do some testing at the sensor itself, you need to test for battery voltage, ground, voltage to the heater, and reference voltage. It could be a pcm, oe ecm issue which would require a replacement part or a re-flash. But I couldn't find any tsb's on it. Also check all of the fuses to make sure that that is not the issue. And again, any exhaust leaks? If so where?

Was this

answer

helpful?

Yes

No

+1

Sunday, February 16th, 2014 AT 1:43 PM