Im having all the problems linked with a bad 02 senser like bad gas mileag, Bad exhaust smell, loss of power, use to idle way to low and even die out once it got warm. so I raised the idle a bit, But my check engine light has not come on. I have a 3.0L 91 runner 165k. My question is, Could my o2 sensor be bad even though my CEL is not on? Anyone?

 

it depends really usually when u drive a certain distance the CEL will go on, reset it, u drive the same distance itll pop on at that same point, if its bad, your engine is most likely running very rich with bad smell of what u were describing

 

my CEL came on for about a week then went off... I though everything was fine... but pulled a code and found that my o2 was bad (it could have been that the people before me that had it got it fixed and they never cleared the code)... so, I changed the o2 sensor, reset the code... and now everything is perfect. I used to have that same strong exhaust smell.

 

Thanx a million guys..... Um... I will try to clean the 02 first because of budget and see what happens but my inpections up in April so. If that doesent work I'll probabley have to bite the bullet and get a new oem one. thanx again

 

Oh yea! How do you reset the code? After replacing.