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Discussion Starter · #1 ·
Check engine lite came on and I reset it. It came on again
scanner reports P0139 code. bank two Oxygen sensor

replaced it. A month later on again. thought it was bad, so had it exchanged
for new one. put in in two weeks later check engine lite on again P0139 code.

Has anyone had this problem. Is the scanner calling out wrong sensor.
Is it really the first Oxygen sensor ?

no exhaust system leaks car runs fine different gas on two months etc

Any ideas
 

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Could be a bad cat. Also double check that there is no leak between the bank 1 sensor and the one thats fouling. A good way to check is to do a SeaFoam treatment. It not only will clean the intake and throttle a little, but it also makes a lot of smoke come out the exhaust. It'll let you know right away if there is a leak anywhere in your ehaust system.
 

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yea it could be a bad catalytic converter.

want a way to get around it?

buy something called an angled defouler

you will never have to buy a secondary o2 sensor again

tip of the day
 

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If only those were legal. If you're in a state that does inspections you will fail for that (if they actually check what they are supposed to). The real problem with that though, is it doen't fix anything, it just keeps the light from coming on it also keep the computer form doing it's job. The sensor is there for a reason. if it's not getting the readings it's supposed to, your car could run like crap.

the seafoam stuff goes partially into the throttle body and the rest goes into the tank. there are a bunch of videos on youtube on how to use it. i would give you a link, but I'm at work and dont have access to it.
 

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I agree, bypassing the sensor is a bad idea. The upstream sensor is usually the one to go out first. And the manufacturers recommend changing 02 sensors after 100,000 mi. When changing sensors be sure to chase the threads w/a tap and use anti-seize on the new sensor threads (a good brand will already have anti-seize on the threads) be wary of off brands, as I found out, the wire harness is sub-standard very little insulation in the casing. I used electrical tape to beaf-up the wrapping, which was too short for the harness.
 
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