I replaced an o2 sensor that was causing my 88 bronco II to run really bad. It fixed my truck for about a year. Then a few days ago it started running really bad with the same kinds of symptoms. It is running extremely rich. I unplugged the o2 sensor and running off the default settings the truck ran perfectly fine.

Is it common for o2 senors to go bad that quickly or what other issues could I have that would cause the o2 sensor to go bad so quickly? BTW no check engine light this time.

 

You may have alot of blow-by(piston rings wore out) from the engine. Or they are just plain junk parts. I went through 3 O2 sensors on my 85 Plymouth before I "got" a good one. Was hell trying to make autozone(boneheads) replace them under warranty.

 

Well the old girl has about 240K miles on her so blow by is very much a possibility. I guess I need to give Advanced a call and see if my sensor had a warranty. Thanks for the reply.

 

> or what other issues could I have

antifreeze leak?

 

No antifreeze leak.

I took the O2 back to Advanced and he said they had alot of problems with the Bosch O2 sensors coming back. He gave me a new one due to it being under warranty but said he suggested if this one goes bad to spend the extra $10 for a Motorcraft sensor.