Contour Enthusiasts Group Archives Forums General Troubleshooting CEL is on but nothing seems wrong

i haven't had the codes read yet my svt has 63000 miles on it and the oil needs changing. does the cel come on if the car needs a tune up? if not what are some small things that it could be. the ford dealer quotes 80 dollars to read it. i have not tried auto zone but that will be next. any clues as to what it could be? thanx

oh and the car is totally stock

yeah go to Autozone- they supposedly read the codes for free- and also - whjen you change your oil fill it to 6.5 quarts-

There are many causes for a CEL, but it does not come on to remind you of maintenance needs. The CEL is linked to the Powertrain Computer Module (PCM)which monitors various conditions thru the use of sensors. If the PCM gets readings that are known to be an "out of spec" issue, usually emissions related, the CEL will come on. If the problem is intermittent, the light may go off, come on again, etc. In any case, the "On Board Diagnostic" system will record the error code, which can be read by the proper reader-scanner. A code number (or numbers) come back, which will then have to be diagnosed. The most common issues on the V6 are O2 sensors that go out of spec and send a wrong signal to the PCM. Also the EGR ports behind the throttle body get carbon-plugged and it appears that the EGR is not opening. Get the code(s) read at Autozone, and then do a search of the posts. There is lots of info on the CEL! Good Luck.

thanx iam going tomorrow to get it checked.although the guy that owned it before me said he did change an 02 sensor. maybe the other sensor went out i guess i will find out

I'm pretty sure your engine has 4 O2 sensors. :rolleyes:

Does Canada have a equivalent parts store that will run codes like autozone, or is there autozones in Cananda?

I saw a couple Autozones when I was up there...

well i had the codes pulled. actually the code. it was 420 which i think is the o2 sensor(s) before that cat. someone tell me if this is right and where is the best and cheapest place to buy these parts thanx

P0420 = Catalyst system efficiency below threshold(bank 1). Possible causes are damaged O2 sensor, malfunctioning ECT, High fuel pressure, Damaged manifold, Damaged Cat converter, Oil contamination, Cylinder misfiring, Downstream O2 sensor wires improperly connected, Damaged muffler/tailpipe assembly, Retarded spark timing., All that straight from the manual.
The diagnostic routines follow from that - If you've got a bad O2 sensor you should have other DTC's from the HO2S monitor (codes in the 100's I think). If you've got no other codes the likely suspect is an exhaust restriction such as a damaged cat or dented pipe, or an exhaust leak.