200kMax

okay heres one that is bugging me. so ive recently got a 0901 which is one of the front o2 sensors. now heres the weird thing. i know when i got the car a few months back, the owner said they changed the front 2 o2 sensors. so they should be relatively new.

so this is whats bugging me. only when i JUST start the car, will i get a bad cel code. when i shut it off and reset the ecu, i can be driving for hours and hours, and it wont come back on. but as soon as i start the car again. bam.. there it is.

so folks. do i REALLY have a bad o2 sensor? or do i have another issue?

whitegold

iTrader: (1)

Its the o2 sensor if it keeps comming back up. Check the wireing harness and change the sensor, if it dosent fix the problem, then for sure its the wires.

Prophecy1

Check your connections and its possible you have a defective sensor. I mean it does happen.

Proph

GodFather

iTrader: (10)

You may have to look into the knock sensor also. I remember I had a bad knock sensor when it tripped the o2 cel. Kept replacing o2 sensors till I finally get the knock sensor cel. After knock sensor replacement, it's done cleared.
good luck

Maxgig

iTrader: (5)

200kMax you may still have a bad O2 sensor. I had a shop change one of mine and I later took my car to the dealer for a free once over. They said I had a bad sensor, so I went back to my mechanic and he replaced it for free. It does happen that you buy one thats bad.

njmaxseltd

iTrader: (19)

A bad KS will NOT set a false o2 code.
A bad o2 WILL set a false KS code.

The reason you only see the error the 2nd time you start the car is because the ECU will only set the CEL if it sees the error happen twice. That would be the 2nd time you start the car after clearing the error.

200kMax

im getting the feeling that it really is just a bad o2 even though it was just replaced. ugghhh... more stupid sensor problems.