So I have a 1997 Lancer Evo IV GSR and love the car and have had no issues with it until now. The other day i went to go to work and when i started the car it started normal and went into high idle but a few seconds after starting it, it started to misfire and sputter for a minute or two. If i were to put in gear and go give some throttle itll sputter and hesitate. If I leave the car for a few minutes its good to drive but still sounds like it is hunting rpms and misfiring slightly. Once up to operating temperature the car drives fine with very slight rpm hunting but barely noticeable and no effect to driveability. It pulls great still and doesn't cut out or misfire when under boost fully warm.

The car is completely stock other than turbo back exhaust. So far i've replaced spark plugs with BPR7ES gapped to 0.60mm, replaced fuel filter, compression test, and sprayed down my MAF sensor. Next thing I was going to do was replace the ignition coils but before I do that, was wondering if there were any other things that i should check first that are pretty common.

Was thinking it could possibly be a sticking EGR or IACV? Or maybe even a faulty coolant temp sensor assuming that the ECU takes its open loop temperature feedback from it. Not really sure and just seeing if anybody had some other opinions or input that may help before i keep throwing parts at it.

Any help is much appreciated

Thanks!

 

Anyone? I've priced out coils and they are rather pricey around 700$. Would like to know if maybe I should go a different route first.