I just recently did the airbox mod seen on the forums and after I did it, it seems as though the ecu has to relearn the new change every time I start the car. It runs rough for about 30 sec and finally smooths out but its throwing engine codes every 1/3 time and I really dont wanna have to ride around with my obd2 comp. with me at all times. A friend told me that it will probably do that until I get an aftermarket ecu. Any help is greatly appreciated.

 

I've got the same problem after doing the airbox mod. The check engine light would come on and then go off once in awhile. Now its steady on, and will get a rough idle ever so often. I tried the DIY on making the ECU re-learn, but it didn't work. trying to find that thread and maybe try it again. Going to clean the MAF sensor as well to see if that helps. I may just reverse the mod an back to being normal again ... lol

 

I found the problem there was a little gap in the hose between the maf and the turbo, and it was taking in more air than the maf was recognizing so it threw off the timing.