When happens if i dont replace O2 sensors

[beanyboy]

They have 88k on them (stock) and im thinking of things that might help my car out as she gets older in age. They have the generic ones at AZ for like $15 each. When do i replace them and does it really matter to the car.. im sure they are pretty gunky by now. thanks

[black98V6]

well when an o2 sensor is in good working order it will help your computer keep the right amount of fuel for the car to run properly. If they are sending a bad signal then it will usually make your car run rich. This hurts fuel economy, fouls plugs and can eventually fry your cat because it won't be able to burn off all of the excess hydrocarbons and will collect them and eventually go to crap. At 88k it's proably not a bad idea and you might see a little better gas mileage. If you do plugs at the same time you will proably do a little better. .... with that said, it's not necessarily a must do at 88k.. might be a good part of an overall tuneup..

[ January 25, 2002: Message edited by: black98V6 ]</p>

[Wolfy]

What else should be done at 60 k miles, i wanted to do o2 sensors, plugs, then what, pcv valce?, egr valve?, how much are those? anything else i should do, maybe new cat?

[DominusEtDeusNatus]

Do plugs and wires, but don't worry about the rest until it actually goes bad. Oxygen sensor and cat are little pricey. I think over $100 each.