Check Engine Light tripped again :(

96SVTCobra · Jul 26, 2006

Ok, I've got an off road BBK h-pipe. Installed the MIL elminators. Check engine light went off. Ran fine for about 4 months like that, but since this April, the check engine light will go off for a few days and come back on for a few months. Any ideas? Car is next to stock. I'm getting ready to buy a nitrous kit and want to get this problem out of the way before that.

wopony98 · Jul 26, 2006

:hammer: Damn I thought my Cobra was the only one that did that. My 98 light comes on and usually stays on for a couple of days to a week or two. Then it will go off and stay off for a couple of days then come back on. The time actually varies a lot as to how long it stays off and on.

I use to think it was because I ran the car hard or when I got on it. I however don't think this is the issue. Hope someone knows.

You can always take it to Advance Auto and they can hook up a diagnostic scanner and tell you what the code says it is that is causing it.

GREG@SN95 · Jul 26, 2006

Is your exhaust leaking?
maybe a bad O2 sensor...

Thats the only thing I could think of given your mods... and I have a feeling that you do indeed have a leak

96SVTCobra · Jul 27, 2006

GREG@SN95 said:
Is your exhaust leaking?
maybe a bad O2 sensor...

Thats the only thing I could think of given your mods... and I have a feeling that you do indeed have a leak

man I hope not. Guess I'll jack it up and tighten everything back up... = pain in the ass. I used an air wrench and everything!

Matt94GT · Jul 27, 2006

im guessing its somthing to do with the 02s/mil elimators...

jpajkos · Jul 27, 2006

Clean the mil's then hook up an OBDII reader get the code. Mine was doing that then i found out it was my gas cap!. Bought a new gas cap and it never came back on.

96SVTCobra · Jul 29, 2006

hmmm it turned itself off tonight... definitely need it looked at. Stupid computer!

tomustang · Jul 30, 2006

get the code scanned

Iceman12 · Aug 1, 2006

My car does that too, although it now spends more time with the light off than on anymore. From what I've seen it has a lot to do withe th temp and humidity on my car. When it gets real hot out my car tends to run a lil rich, so the CPU notices it has no cats, but for example:

if I drive to my friends house when it is real hot and humid and the light comes on, if i hang out there till it gets dark and cool, and the car completely cooled down, (when temp goes back below 160 the CPU will take another look at O2 data and re-decide if it will use it, MIL light on = not using O2 data), once the car warms back up ususally the light will go off again.

So with a lil planing I can now pretty much keep the MIL light of all the time, which at least on my car makes it run a lot better.

96SVTCobra · Aug 3, 2006

Iceman12 said:
My car does that too, although it now spends more time with the light off than on anymore. From what I've seen it has a lot to do withe th temp and humidity on my car. When it gets real hot out my car tends to run a lil rich, so the CPU notices it has no cats, but for example:

if I drive to my friends house when it is real hot and humid and the light comes on, if i hang out there till it gets dark and cool, and the car completely cooled down, (when temp goes back below 160 the CPU will take another look at O2 data and re-decide if it will use it, MIL light on = not using O2 data), once the car warms back up ususally the light will go off again.

So with a lil planing I can now pretty much keep the MIL light of all the time, which at least on my car makes it run a lot better.

my thoughts exactly. it's been under 105 here recently (it was over 105 when the light tripped) and it's been off ever since. Though humidity seems to have no effect on it. As tonight, it was 93% humidity and 90 degrees and no check engine light. piece of shit!