I posted last week with engine problems, turned out it was the front O2 sensor. Had replaced it 11 months earlier, it was an OEM part from Bosch, purchased at NAPA and they replaced it under a 12-month warranty Interestingly, the price on the exact same new sensor dropped from $132 in December 2005 to $78 last week .

 

Anyway, there were no codes thrown, no CEL, just running bad when warmed up, especially at idle.

 

Removed O2 sensor didn't look bad at all, no obvious visual things wrong - guy at NAPA smelled it and pronounced it didn't seem fried.

 

Any ideas what could cause this? Original sensor lasted 60K miles and threw all kinds of codes when it crapped out. This last one lasted 10K miles without triggering anything.

 

THANKS in advance. - Joe

 

2001 Forester, non-turbo

Maybe it's not an O2 sensor causing the problem?

I posted last week with engine problems, turned out it was the front O2 sensor. Had replaced it 11 months earlier, it was an OEM part from Bosch, purchased at NAPA and they replaced it under a 12-month warranty Interestingly, the price on the exact same new sensor dropped from $132 in December 2005 to $78 last week .

 

Anyway, there were no codes thrown, no CEL, just running bad when warmed up, especially at idle.

 

Removed O2 sensor didn't look bad at all, no obvious visual things wrong - guy at NAPA smelled it and pronounced it didn't seem fried.

 

Any ideas what could cause this? Original sensor lasted 60K miles and threw all kinds of codes when it crapped out. This last one lasted 10K miles without triggering anything.

 

THANKS in advance. - Joe

 

2001 Forester, non-turbo

 

So many things can go wrong to cause what you describe. SOunds like you may have a vacume leak, when was the last time the air box was opened up.

An OE o2 sensor only comes from one place, the parts counter at Subaru.

O2 sensors wear out with age, thats how they are designed.

 

To find a vacume leak get a can of carb cleaner and start sprating hoses and gasket surfaces, and see if the engine rpm changes. Actually firt (if its now winter yet) use a garden hose and get a feel for in what arear of the engine to look for. Also this would tell you if its the wires causing it (you can see sparks)

 

nipper