Help, i posted a thread a few weeks ago about my Jap STI 4 running a bit rough around 3000-3500 revs, i did put in NUL the once but haven't since. Now when started for the first 10mins or so i get a lot of popping and spluttering from the engine. Have reset the ECU to no avail. Appreciate any help.

Cheers Bob

 

Don't know if it's the same as yours, but I had a similar prob on a '98 uk spec turbo. My old boy (ex RAF Lancaster electrician) swore me down the prob was electrical, and so it proved-- a spark plug lead breaking down under power. It didn't show up on the dealer's diagnostic , either.

 

Probably leads or coils.