I don't know really - you must check your engine error codes to see if they recognize a problem - otherwise i guess you need to check your hardware. My experience with Audi dealer techs is such that I could not begin to guess what they will/won't find and how much it will cost to fix it. If its not under warrenty i would take it someplace else.

 

I have a 2001 Audi S4 Avant with 105,000 miles on it. Overnight I developed a loss of horsepower and or torque, so my independent Audi mechanic did the computer diagnostics even while driving the car but no trouble engine codes or anything has shown up. He changed out the MAF, the air cleaner, and put in some 44K injector cleaner with no significant, if any, improvement. He tested the oxygen sensors before and after the catalytic converter, checked vacuum leaks, turbo boost and all are within Audi parameters. He said it is running lean for "optimum" performance but not this significant..

Should I reset my ECU by unhooking the battery to see if the computer just needs reset (if I have the radio code)?

What next?

jcarriso
OK

 

I know i saw this on another forum..just not sure which one..

Id take it to another mechanic to get another diagnosis on it.

How much loss are you talking.. nor do i think that resetting the ecu will do anything...

One would think youd be throwing a code or a leak somewhere..

Waht is that thing with safe mode???

 

I'm scheduled to take it to the dreaded dealer next week. No engine codes or anything have been detected by the independent Audi mechanic so far. Even the turbo checks out OK. I've never heard of "safe mode". What is this?

 

haha... i didnt even read the rest of the thread.. i meant to say limp mode.. as they were talking about before.. yours sounds like the limp mode more to me than audifasts problem.

audifast.. i think yours sounds like it the gauge is not connected properly.. does the gauge move at all... when the car is off it should be at 0... when idle it should vacuum at 20 mmhg or so.. and then go up with throttle. if its not going up any its not getting any read so itd be like a loose hose or something not connected properly.

 

Is limp mode something the Audi mechanics will know about? Is this something that can be fixed inexpensively or do we have to take apart the engine?

 

honestly.. i dont know.. ive only just heard about it and what its like when youre in it.. i would think theyd have some idea.

 

Find some one near by who can vag it for you, and then post the error codes.
Its definitely in the limp mode.

I was getting Positive Deviation (overboost) code recently, before my car went to limp as well. => Boost Leak somewhere / N75 issue, but that was for me.