Anyone know what would cause a check engine light to flash at full throttle? Every once in a while it will also backfire. Could it be something with timing or ignition? Any help would be greatly appreciate

 

It's a bad misfire. STAAAHHHHPPPPP before you lift the head and figure out the issue. Or if the car is tuned, the tune is setup to flash the CEL with a certain amount of knock. In which case, also STAAAHHHHPPPP...lol

 

+1....what he said, definitely stop going WOT till you figure out the problem. A little more back story on your car would help people steer you in the right direction.

 

Is it flashing slowly or rapidly? I put a Tephra Rom on my car and its set to flash slowly at 3 counts of knock and fast at 6 counts. If its super cold mine will flash slow as boost is coming on and goes away. If yours is staying flashing past the 4-5k mark I would say you have some serious tuning issues.

 

Knock at any point during WOT is an issue on a tuned car, and should rectified. However, having the light flash at 3 and 6 counts is very low.

 

It will rapidly flash 3 times. But it's odd it doesn't happen every time I go wot. And happens around 5 to 6 grand

 

The car is also tuned. It was doing as soon as I got it back from being tuned. I know the tuner was having trouble tuning it because it took like a week from them to get it right but they never said anything about the light flashing

 

You should find a new tuner. Cut your losses with the tooner you just got it back from. A week to tune a car is absurd.

 

I've heard some tuners say you should aim for no knock during a 3-8k pull, and I've also heard that anything up to 3 is acceptable. Guess its just preference. I self "tune" my car and anything over 3 I either add fuel or take out timing/boost until it lessens or goes away.
Or just add more methanol to my water/meth tank...

 

I had knock around that rpm, turned out my fuel pump went bad. Still idled and drove normal but at wot, it would start knocking.

 

My advice is you should drop the ~$130 dollars on a logging/tuning cable w/ evoscan so that you can talk to your car. As an evo owner I can guarantee that it will be the greatest bang for the buck you could possible spend on your car. If you can post to an internet forum you can figure out how to set up data logging and some light ecu adjusting. Your tuner has given you a new ROM image for your ECU that has many very cool features with different basic settings that you can adjust, and having the cable will allow you to do so without having to go through your tuner. The CEL Light flashing is just one of those features and it too can be adjusted if needed. All the information you could possible wan't about logging and tuning the evo is in these forums. The Evo's ecu code has been disassembled by this community and rewritten to basically turn your stock ECU into a standalone, capable even of Speed Density mode if you wish it. All you have to do to tap into that potential is buy that cable (and a few other things for SD).

 

Very well said

 

Could be built into the tune I'd buy the cable as well

 

Something else to consider it could be false knock caused by something banging on the engine or drivetran. I would check all around the engine bay for loose object and check your downpipe make sure its not hitting the transfer case or cross member.

I have a problem with my downpipe banging the cross member wich occasionally triggers the cel flashing.

would still get a data logging cable anyone with a tuned evo should have one.