I have a 1999 Audi A4 2.8L and I have recently installed an aftermarket intake. Since then (couple weeks ago) the idle is somewhat unstable at low speeds or while clutching, to the point where it even stalls occasionly (happened twice). Now the CEL (check engine light) appears as soon as I start up the car and remains lit. So what should I do? Should I re-install the stock air box? Maybe everything will go back to normal? Or should I replace the MAF(or whatever is actually wrong) and keep the aftermarket intake? Or will the problem just re-occur? Also I heard that the idle and stalling problems could be due to the Idle Control Valve being not clean. I know that you can clean it, using carb/throttle body cleaner. The hard part is getting it out.
Any thoughts would be great.
Also I've have ordered a engine scanner and will know the exact problem code as soon as it arrives (a couple days).
Thanks