Check engine light possibilities. - Toyota Nation Forum : Toyota Car and Truck Forums

thetimmer · 05-13-2004, 12:43 PM

Got my check engine light on again. It seems to go on for about 2-3 weeks then off for about 2-3 weeks then on again. Thought it was the rear O2 sensor and that it was cold but now that we're in the warm part of the year, that can't be it.

I recall that the last time it went off was right when I turned on the A/C. Maybe it a co-incidence or maybe not.

What other possibilities could it be for when the light comes on and off on it's own?

repinS · 05-13-2004, 12:52 PM

Even if the light isn't on, codes can be stored in the ECU. Pull 'em and find out.

thetimmer · 05-13-2004, 12:54 PM

and found out fer free. Thks for the advice. Maybe I'll pick up a Edmonds or Haynes book while I'm at it....if they even got it.

Nico · 05-13-2004, 12:55 PM

It can be MANY things believe me. Is your engine running well btw ? I think your best bet would be to go for a diagnose. I think they do it for free in some places in the US but I am not sure ...