I have a 2004 subaru wrx with some mods on it including a ecu reflash.
Went to replace the spark plugs yesterday and put everything back together and the engine doesnt want to stay on. Almost like the timing is off. this is not the first time that i replaced the spark plugs so i know that i couldnt have put the cop harnesses on the wrong one.
the engine cranks and turns over then dies right away almost like the map sensors not plugged in. it feels like you need to give it some gas but if you do so the engine dies even faster.
So i went back and double checked everything and even put the old spark plugs in and still nothing. I checked fuel pressure which i have. i looked at the new spark plugs and you can see that they have been firing which means i have spark so the coil on plugs are good. i dont know anymore.
i was going to check the coils on their own but am not sure how to do so. how do you check the coil on plug? what would be the likelyhood that its my ecu? i've unhooked the battery before and never had that happen.
hooked up my scanner and no codes show up because the codes get erased when i unhook the battery and i cant get the codes to come up cause the engine wont even stay on.
I know you said you checked but I would make sure the coil plugs are plugged into the right coils, the white ones go in front and the black ones go in back. Then I would check the connection to the maf. You said that you disconnected the battery was the ignition switched to on when you did? If it was you may have fried the ecu. But I would check everything else first.