tator152

well i have been having some problems with my car running rough/missing and i was wondering if it could maybe possibly throw a code without the cel coming on.

DarkDigital

It can but most likely no. Given enough time it should though.
Try running a bottle of lucas fuel cleaner and a full tank of 93 through your tank and see if that doesnt help. Sometimes you'll get bad gas and that will cause your symptoms.

dastangman

Yeah, you can actually...I can't think of what they're called, but there's a few of them, I had one that dealt with an interference with the computer, but it really wasn't anything at all. I'm sorry I can't think of what it is right now, but a Ford dealership would probably be able to help. It has something to do with a special key sequence of having key in, igntion on and some other things...

There's also the chance of it being turned off manually via some program by a previous owner...although the tuner would probably be with the car then.

98redstang

Yes you can ive had it. My car was running like crap and there was no check light but i scaned it anyways and i had 2 codes.

cliffyk

The EECv system stores what are called pending codes, things like infrequent misfires, etc., and does not trigger the SES lamp unless they re-occur repeatedly, or during the next drive cycle. They can be tretrieved with a scan-tool.

"Running rough/missing" should trigger the SES lamp if it happens consistently. However as misfire is detected by analysis of the crank position sensor signal to gauge the angular velocity and accleration of the crank shaft it takes pretty much a complete misfire to trigger the code.

I had 3 Granatelli COPs fail in a period of 2-1/2 weeks (fortunately I got them for about 1/2 cost), and drove over 50 miles in one instance with a very bad misfire with no pending or continuos DTCs--I.e. no SES indicator...

In your instance the first thing to do is check the plugs, and the COPs' boots and springs...

99BlackPonyGT

when i had the 2v in my car, i was missing on 3 cylinders and had no light and no codes

cylinders 5 and 6 had coolant in the plug wells, along with a blown COP on cylinder 5, from a cracked intake ..cylinder 8 had oil in the plug well from a blown valve cover gasket

i had it hooked up to a laptop diagnostic program, took it for a drive, and found all the cylinders that were missing...

if having the codes pulled revelas nothing, your local dealership should be able to run diagnostics on it and tell you which cylinders are missing...around here its about an hours worth of labor

if youre more hands on, pull each COP and check the plugs and check the COPs for spark...also check your fuel pressure, your pump may be weak...my car had to be towed home due to a bad fuel pump, but it fired right up and i drove it an hour on that same pump *i forgot it was messing up*

**edit, also...it never hurts to do a tune up...if its been awhile, maybe think about putting new plugs in it, cleaning/replacing the air filter, and putting in a new fuel filter....if its just running a little rough, intermittently, it could be something that simple

0949er

Also, It wouldnt hurt to just take your car to a shop and have them scan it for codes... they should do it for free, and you can at least see if anything comes up.