OK, so I have a 1994 4x4, 302, manual with 257,000 miles, have owned since new. The oxygen sensor has never been changed. I read that it should be changed every 30,000 miles. Anyway, not throwing any codes or anything, truck runs fine, although it does seem like its lacking a little power, every once in a while I will drive it and it feels like it has an extra 30hp. I have no idea, but could it be that I need a new oxygen sensor? I also read that sometimes it wont trip a CEL, and if its bad, but not real bad, that would make sense. For $45 or whatever they cost, might be worth it, just because, but anyone have any thoughts on the subject? Also, I imagine after 18 years that booger may be pretty stuck, any tricks on getting the old one out? Once out, is there any way to test them? I guess I just think it probably should be changed....but.....maybe not.

 

Change it...that's a pile of miles for an o2.

 

Yeah, I know it is, but no check engine light or anything, so never changed it. Thinking I may do that this weekend though. Should I expect to see improvement?

 

Start soaking it with PB Blaster or another VERY good penetrant! It should have been replaced a LONG time ago! Just because they don't trigger a CEL doesn't mean it isn't bad, it will however affect your fuel mileage and overall fuel mixture in the engine significantly.

 

Yeah my bad... It has dropped mpg and a little power. I think I will be doing that this weekend. Does it help to have the exhaust hot when removing?

 

I have always found that a PB Blaster soak for about an hour and then warming the engine makes it a very easy job. Use so anti-seize when installing the new one.

 

Thought about letting it soak overnight..might not do any more good than an hour though. I'm betting is going to be a booger to get off after 17 years....

 

o2 Sensor is like 2$28 from summitracing if you can wait 2 days or so for it to come in. Save about 20 bucks.

 

Already picked one up, along with a new thermostat, spark plugs and radius arm bushings. :-)

 

It's $28 from Advance if you use a coupon code.