double06

When I start the car in the morning and drive it about 4 miles or so all of a sudden the engine will run rough for about a minute as give it a little gas and then all of a sudden the car runs fine for hours no problem. Is this something in the transition from open to closed loop? This happens only on cold starts if I stop in a gas station and get back in no problems. Sort of happened just recently not sure what I did to bring this on. I did fix a vacuum leak but not sure why that would cause this.

User Omega

Is this car modified with an aftermarket tune or on the factory tune?

double06

Ah yes excellent question. Cam, headers, intake, heads redone, ported stock TB, Halltech intake and yes a tune has been put in it and has been fine for a year.

schpenxel

Needs to be logged, otherwise we're just guessing. The switch from open loop to closed loop happens quite fast unless it's been changed, well under a minute on mine. Maybe someone set the tune up different on yours.. need to see a log of it happening and the tune to really have a chance at figuring it out IMO

speedz06

Id like to see what you find out.

double06

Well I unhooked the battery for about 15 minutes and put back on - seems to have fixed the issue. Maybe when I fixed the air leak the computer was use to it (the leak) and by disconnecting it, it relearned it with the vacuum leak fixed. As I said mine was for a brief period of time between 4-5 miles from my house.

double06

I also cleaned the MAF sensor in the front and that helped a lot. It must have gotten dirty or something when I had the cold air intake apart. I also tighten the wires and connections to the MAF and throttle body as they might have been loose.