I recently bought a 00 S4, 6 spd with about 120k on the motor. about a month after i bought it the syncro's in the tranny went out and had to have it rebuilt. while the tranny was out i had the clutch done and pu in a short shifter and flywheel. it also has an apr 93 oct chip. whenever i give it to much throttle in 3rd or higher it begins to shutter until it gets to about 4500 rpm. also my boost peaks at about 10 psi and settles to about 7-8. the person i bought it from showed me a receipt for the chip but i am not sure if it is just a boost leak or what. any advice is appreciated.

 

I have a '00 S4 also and the same problem was happening to me. Took it to my mechanic and ran some test, found out the Mass Air Sensor was on its way out. It was cousing the engine to miss fire when I got on the throttle to hard.

I would start there and cross your fingers. Also check the D/V's if they are stock, they probably need to be replaced.

Good luck!

 

yea the stock diverter valves dont work well with a chip and its a must to upgrade to somethin a little sturdier...what were the symptoms of your synchros going? i think mine might but im hoping just a tranny fluid flush will fix the notchyness of my shift. when its cold out its sometimes difficult to put it into first or reverse so im like ehhh... cant really afford a tranny rebuild right now

 

when my syncro's went out it was really hard to get it into first and i couldnt shift above 4000 into 2nd. but i guess its time to get some better diverter valves. never hurts to upgrade. where can i get a Mass Air flow sensor?

 

Got new diverters i went with bosch 710N's and got an rs4 maf. the missing has been solved for the most part, but it will still miss from time to time. but i can already tell it is running much stronger. if you cant afford a rebuild you can always try to find a used tranny.

 

so your running rs4 maf with what stage? did you modify your airbox and accordian pipe? i was told rs4 maf wouldnt work with stock fueling. its so hard to get info on these things. ive been having similar problems for a while now. tried alot of things still missing big time

 

You're correct, an RS4 MAF is not a bolt on replacement for the S4. The housing alone won't mate up to the air box /accordion hose. Not to mention, it will run like complete crap without an ECU mod. It's not even worth installing unless you have K04s or larger.

He probably got an S4 MAF, unless he did some modding to make it fit.

 

well i ordered a rs4 maf and it bolted right in place. i didnt have to do anything to the air box to make it fit. so it could just be a new s4 maf. i couldnt tell the difference between the two that i have in the time that they were both out because it was a quick in and out.