I just had my Timing belt & water pump replaced along with,
both turbos rebuilt
Valve cover gaskets
Out put rear differential seals and the pinion seal
New Air Cleaner and filter
Fuel Filter
a/c Condenser
And today did mass air flow Sensor
Optima Battery

And im still in Limp mode, when i plug in the Mass air flow sensor the car acts like its not getting enough fuel or having poor compression.. will only accelerate if you press the gas ever so slightly then it shakes and again acts like the fuel filter is dirty or something.. the codes that come up are.. ABS, and traction Control.

I take the Mass air flow sensor out and the car runs fine, but acts like the turbos are just dumping... it has no acceleration, but doesnt shake or try to starve itself. both the previous codes come on but it adds the check engine (cause of mass air flow being out of service)

We've checked and double checked the wiring and electrical codes everything is in order.

Any body have any ideas what could be causing this limp mode? The car drove fine before i took it in now its acting up. Please help the car has been out of commission for 5 weeks already and the mechanics are getting pissed they cant figure it out.

thanks

 

Vacuum lines. I have a 2000 s4, and the last couple times mine has stuttered or shaken when i press on the gas, it comes down to a vacuum line somewhere being not hooked or broken. If you can unplug the MAF sensor and the car smooths out, the best guess is a vacuum line.

 

Alright, I'll give that a try. Thanks

 

hey man i know i owned a b5 a4 but had a similar issue and mine was about a 500 dollar issue when you run codes see is you can see how many volts are going to your MAF and if they are over 12 there is your problem. were all of your wires go some of the wires have welded them selves to each other and is sending to much power to it that was my problem goodluck with it

 

sounds like something wasnt plugged back in.