Check Engine Light Stuck On. Code 21.

[druhanson55]

:chairshot:I can't get the light to go off and code 21, (Main O2 sensor signal (left)) won't clear. I pulled the fuse with no luck and pulled the -battery cable overnight. When reconnecting the battery cable the cel light is still on and code 21 is still present. I don't understand how the code can show up again before running the engine?? Does this suggest that I have a short in the O2 sensor circuit? The car runs fine but I need to get this cleared so I can get my inspection sticker. All help is greatly appreciated !!!

[Lambo Travis]

:chairshot:I can't get the light to go off and code 21, (Main O2 sensor signal (left)) won't clear. I pulled the fuse with no luck and pulled the -battery cable overnight. When reconnecting the battery cable the cel light is still on and code 21 is still present. I don't understand how the code can show up again before running the engine?? Does this suggest that I have a short in the O2 sensor circuit? The car runs fine but I need to get this cleared so I can get my inspection sticker. All help is greatly appreciated !!!

(bump)

I too have the code 21 -

haven't replaced anything yet, tho -

just hadda buncha other things done (timing belt, water pump, rotors, etc...) & CEL is still on w/21 showing -

also -

"TRAC-OFF" stays on -

I read in another post that it will stay on as long as CEL is on, possibly even if there is no trac prob -

I'm DEFINITELY no mechanic, so sorry in advance if I worded this "stupid" -

thanx for help/advice -

~T~

[SKperformance]

I would check to make sure the wire is not melted.

[bicol-ini]

then you replace the O2 sensor? if you then check on wiring, maybe some loose in there