Just installed the 93 oct. GIAC chip in my 2002 s4 today. The chip was one i bought here from the forums.. it was a full ecu already chipped. The box is an m box.. and my stock box is a t box. I looked through the forums and they said they were interchangeable.. but i'm experiencing some problems. The car starts and idles fine.. but when i rev.. it sputters as it revs up and than falls all the way back past 1000rpm and than stalls. Any ideas what's happening? I thought it might be because i was running 89 oct. So i threw the original ecu in and ran it until it said there was 0 miles left and than i put 93 in.. thought it was running better.. the rev up didn't sputter as much but it still stalled on the way down. Any suggestions or ideas would help. Thanks.

 

try cleaning up your MAF and replacing your vac lines.

 

Cleaning MAF.. which VAC lines.. sorry if that's a dumb question.

 

02's need to be replaced.. could that be why?

 

all the vac lines you can see. not sure about the 02's. you gotta check everything. lots goes wrong when you add boost to a 10 year old car.

 

tbb tore

 

TBB is fine.. already upgraded.. no dry rot or anything.. only 6 months old.

 

got codes? vcds ftw.

boost leak test? test to max requested psi.

plug gap? 0.025"

all good things to check when upgrading software.

 

Replaced TBB.. torn again. Replaced MAF.. throwing a p0102 code.. Still throwing code. Unplugged MAF.. is running now. Will boost leak test tomorrow. VAG comes in a few days and will post what it says.. any more suggestions in the mean time?

 

Hey guys, found a boost leak after testing it yesterday, here's the picture of what hose it is, highlighted in red.



Also here is the hole in the hose itself



When i found the hole.. i took the hose off, and since it connects to the n75 valve.. i removed it from there, but when i did the n75 valve pretty much feel off of the hose, spring and all, like it was barely attached. So i ordered one from audis4parts, and am now waiting for it to come in. Do you guys think that small of a leak, combined with possibly faulty n75 valve, would be enough to throw the p0102 code and make the car stall upon starting? Also any suggestions on vacuum hose sizes for replacement, auto zone has a kit that has 10 ft. of 4 mm., 5 ft. of 6 mm. and 2 ft. of 10 mm. hoses. Here's the Info

Think that would work? If i'm buying the kit i guess i'll just replace all my hoses. Any more input from you guys would be great. Helped a lot so far.. have a feeling i'm getting pretty close to having a working, chipped, S4 pretty soon.