Well, the other day afterfilling up with gas my A6 2.7T immediately started hesitating tremendously. Severe loss of power. I thought at first it may have been the gas I just purchased, but after driving through several tanks it continued. I replaced the fuel filter shortly thereafter, but no change. Took it to a local Audi shop, they told me it was the MAF and Exhaust Temp sensor. After hearing their hilarious quote for replacement, I ordered the MAF online and installed it myself. After the install, nothing much changed ! It does idle smoothly now whereas before when idling the rpms would jump every 10 seconds or so. It still hesitated quite a bit in initial acceleration. I then changed my air filter. This actually improved conditions more then the MAF. Now there is still hesitation, and I can't just stomp on the throttle, but it does seem to be more linear in rpm's when accelerating.

I took it to another shop to have the ECU checked. Found out my left O2 sensor is bad, but they said it shouldn't have that much to do with my problem. They recommendeda fuel pressure test and an injector cleaning.

So, I have replaced the fuel filter, air filter, and MAF. Do any of you know what might be the problem? Hopefully not the fuel pump or fuel sender...both very $$$. I'm going to have the fuel pressure tested next week.

I really miss my bi-turbo under hard throttle! If anyone has some advice I would appreciate it!

Thanks,

Brent

 

Sounds like the same problem im having ill also do what you did and see what happens

 

check and see if your spark plugs are bad. if this is the case, its like a $20-30 fix. Have you run the codes on your car to see if anything comes up, thats your best bet for right now. Also, it may be a vacuum line leak...these happen ALL the time, and are a really cheap do-it-yourself fix as well. I had a vacuum line come apart, and my car lost at least a third of its power instantly.

Also, if they told you to replace the exhaust temp. sensor, why haven't you done that as well? I'm assuming its another easy repair and it might be contributing to the problem. Sounds to me like a vacuum leak though....

LampyB.

 

oh, and the 02 sensor might contribute to a small lack of power, but all in all that should just hurt your idle and cause it to bounce a bit. When you replace the 02 sensor, I suggest doing both at the same time, it'll make your car a lot happier in the long run.

LampyB.

 

Get a code reader and post the codes.

http://search.ebay.com/audi-code-reader_W0QQfromZR40

 

The EGT, will cause this, so can a bad O2. You need to see if there any stored codes. If it is the EGT, the car will run poorly until you fix it.

the sensor along is like $400, they are a little of a PITA to replace.

 

Thanks for the info everyone. I'm ordering both O2 sensors next week, and new spark plugs. Also have my fuel pressure test/injector cleaning this week. Will keep everyone posted.

I will also pick up a VAG-COM to run engine codes...any recommendations on brand/type? There were several choices...