Hello, I was thinking about replacing my o2 sensor because I drive a '90 GXE and it still has the original sensor. Most people on here say to replace only when it goes bad, but what about old age?? I think I read a Bosch ad that said to replace every 30k miles, but I'm not sure.

Thanks

 

I would replace the O2 sensor only if goes bad.

 

yeah, aren't they kinda expensive?

 

Dude if your 02 sensor is original REPLACE IT. mine only had 60k on it and after replacing it I got immediatley 15% better fuel economy.

Also I had tested the 02 sensor with the on board diagnostics and it said it was well within spec. but I knew with 60k on it that it needed to be changed.
If you let your 02 sensor get worse and worse, the engine will run rich (wasting gas), possibly ruin you catalytic convertor (over heated due to extra gas to burn), and rot your exhaust system.

go to www.nopi.com they have an excellent price and I hear they ship real fast.

 

That's what I have been thinking also. Should I change it? My '97 has ~54k right now, and recently the gas mileage is really bad, like 19mpg (mostly local driving).