I was driving down the road yesterday doing exactly the speed limit (45), not accelerating hard or anything and my check engine light started flashing. It flashed about four times and then turned off. I am not sure why it started flashing? I turned around from my trip and just drove around my local area for a while and everything seemed okay..... I just assumed that something got triggered for a second because of all the humidity we have been having. (that could be totally inaccurate lol). Is this a problem or nothing to worry about? Also this question is a little off topic, If I were to get a test pipe, and the CEL were to go off, what happens to the car? I read you had to disconnect the battery? Okay well thanks guys.

 

It was misfiring bad enough to damage the Catalytic convertor. There will be history DTC's stored. Take a look at the CEL sticky at the top of the forum for more info.

 

MRI?

 

I am not trying to be an a$$, but are you sure it was a CEL and not the Maint. req. light? That will flash while you drive when it hits that 'magical' number. Again, I am just asking.

 

sounds to me like it was the maintenance light. which is based upon mileage, as an indication to change your oil.

 

here in japan we hit trip button to clear maintaince light...

is this maintaince light or check engine light?

 

Yeah i said it was the check engine light.... the cel was a different question.... So since my check engine light flashed, it just meant it was time to change my oil? I thought it would stay on or something? thanks

 

I'm not trying to give you a hard time, but I still am unsure of which light is causing the dilemma. If it was the MRI then it is just a reminder to change the oil and what not. When the MRI comes on the first time it blinks. If it is not reset, then eventually it will come on and stay on until it is reset. If your Check Engine Light came on that is whole different story, especially if it was blinking. If it was your CEL/Check Engine Light then you should see if your ECU is storing any DTC's like SlowS2k said. I have never seen a CEL come on and blink, only to clear itself moments later. I don't see how the ECU would determine there was a problem, throw a DTC, then cancel it within moments. I think even to clear the gascap DTC it takes a couple trips. Also, I remember reading recently SlowS2k saying that the blinking CEL is reserved for severe misfire DTC's, if that's the case I really don't see how the CEL could clear itself so quickly.

MRI= Maintainence Required Indicator
CEL= Check Engine Light

https://www.s2ki.com/forums/index.php?showtopic=378792

 

Blinking CEL= Misfire bad enough to damage the convertor.

The only exception I have found with this rule is on a vortech equipped car when the Timing controller bugs out it can cause the Blinking CEL and not store any temporary DTC's.

Unless you've got a Vortech, that's not your problem.

 

Good deal, I appreciate all the info.

EDIT: Will a blinking CEL ever clear itself? I know a normal misfire DTC (P1303)can clear itself (on a civic anyway), but not without a couple driving cycles.

EDIT: Dumb question, there is no way to get in a couple driving cycles with a blinking CEL. Duh...