ok so ive had this 2002 a4 for a few months.
when you push the gas all the way down the RPM's climb very slowly and it gets really loud. you can hear the turbo spinning up but it doesn't pull like it's supposed to. It actually accelerates faster when you push the pedal less than halfway.

it's at 120k


i've replaced:

fuel pump
fuel filter
DV
n75
spark plugs
trans fluid
oil pickup screen
oil pump
timing belt
water pump

i have cleaned:

IAT sensor
MAP sensor
throttle body
MAF sensor

the wastegate actuator is fine and works as it should, i have done the n249 bypass.

i am leaning towards a clogged/bad cat, or possibly MAF?

scanned with vag com, no codes, pressure tested holds 15 psi

I AM COMPLETELY LOST AS TO WHAT IS WRONG>>>
PLEASE HELP

thanks
-Josh

 

welcome to audi. U have a car that is over 3000 pounds with a baby engine and and a baby turbo. It wont go fast but it will go and look good going too. Plus u have no codes. That tells me ur car is running fine no clogged cat or anything. IF u want the extra umphhh take u car and get it chipped. it really wakes it up.

 

What's the vag reading on your maf?

 

Try doing a throttle body adaption. To do this turn the ignition on and hold the gas pedal don't for 15-20 seconds. Then turn the car off and then start it.

This should help improve the responsiveness.

Good luck!

Jason

 

i will try the tb adapt when i leave tonight. i don't have the full vag com, just a generic cable and the lite version. i'm guessing I would need the full to read a specific sensor.

as for the baby engine/turbo...are you sure? i previously owned a 2002 a4 1.8t with the fwd CVT transmission and that car FLEW compared to this one. Now I know that the quattro takes some power out of the drivetrain but I wouldn't think it would be this different? Since my first post I added a boost gauge and it appears to be boosting fine @ 8psi for an AMB engine.

what do you guys think?
thanks
-Josh

 

Are you going like 35-40 on a city street? Because the car is usually already in 5th gear at around 2200-2500 rpm at that time, and it's not going to go anywhere, and it's going to take it's time doing it to. Yes, I said that right.
like the others said, chip it, maybe put in a test pipe and exhaust, you might be happier.

 

get a hfc. That clogged cat will robb the car of alot of power. then chip it!

 

Well, I wouldn't do anything performance related unless you were absolutely sure the car is in working order.

Its really hard to tell you anything though from our stand point. Without scanning your car and driving it for ourselves we'd just be guessing. Scrounge up some bucks for a diagnostic fee and take it in to a dealer. You don't have to commit to any repair, Just pay the diag. Its cheaper than keep throwing parts at it

 

i have an 04 b6 1.8 6 speed with almost all the same parts replaced as this guy ^^ and i am having the same problem!!

it seems at WOT the cars RPMs stop climbing and it almost loose power. but as i let off the throttle it starts to pull harder as the throttle body is closed to just the right spot. i have the idea that for some reason the AF mixture is off. it feels like the engine is leaning out or possibly becoming too far too rich.

its has a code but its only for the deleted cat/test pipe.

no boost leaks, no cracked hoses

this is really stating to **** me off please help

 

so i took the upper o2 sensor out and took it for a drive....no change in performance so im guessing the cat isn't clogged....

is there a way the CTS or possibly the IAT sensor could affect the acceleration?
how about the throttle body? do those typically go bad at my mileage (120k)?

when i floor it from 5mph, it gets loud, slowly climbs in rpms and accelerates very slowly, then i feel a jolt (like a transmission shift even though it's in the same gear) and it then seems to accelerate a lot faster and quiet down. by that time i'm going 45mph

does that seem like a throttle body issue?

thanks
-josh