2000 A6 2.7t manual-NO throttle response/lots of engine codes/idles normally/NEED HELP!

Maintenance/Repairs
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1

Here is an interesting one… Last year I bought a 2000 Audi A6 2.7t 6-speed manual sedan with 140,000 miles on it off of Craigslist. After arriving home 30 miles that same day there was smoke billowing from the exhaust. It was determined that the “new” turbos the car had were no good. The company where they were bought (and installed by the previous owner) actually did replace them for free under warranty but as we know the labor is extremely expensive as the motor and transmission in this car have to be pulled to access the turbos. Once this exchange of turbos was completed, it was found that apparently while driving home on bad turbos that day, cylinder 6 had “cracked” and now that the car was back together it would no longer start due to no compression. By now I was about to give up but I had found the same car at a junk yard with 80,000 miles that was rear-ended and I bought its motor. Now I found myself pulling the engine from my new used car (that I still had only driven 30 miles in 6 months by now) and doing an engine swap. Finally, I had the car I have always wanted and it really did drive great… for 30,000 miles. So today this car sits in my drive way with 170,000 miles on the body, 110,000 miles on the motor, and 30,000 miles on the new turbos.
Now here is the kicker. One day last month while driving, the “check engine” light came on along with the “EPC” light and the car lost all throttle response. It was determined that when you shut the car off, then opened-and-closed the hood, the car was then drivable again. This would happen once a day. After a week of this, it started to happen twice a day. As of today, the car no longer resets by this method or any other method I have tried (disconnecting the battery over night/ clearing the codes with the computer) and is totally unable to be driven because there is no throttle response. The car starts perfectly every time and has no problem remaining running, the gas pedal just has no response.

Also, the engine codes vary every time you plug in the computer! But here is a list of the last reading: P1639-P1388-P1633-P0102-P0341-P0346-P0106-P0237

Any suggestions would be extremely helpful as I am running out of patience, time and money… Thank you in advance.

Jay

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I, 4 years ago graduated from an automotive tech school, And while im not a master mechanic yet, I have to say one of the most common issues you’ll fine in electrical faults is a bad ground. The fact the engine was replaced has me suspecting perhaps a ground wire was not attached to its location as securely as it should have been. a simple grounding issues can be jostled by closing the hood of a car enough to make contact once again. Most modern cars have a “fail safe” mode or limp home mode depending on who you talk to. If the ECU determines there is a fault that has a potential of causing major damage to the engine it will go into this fail safe mode and cause simmilar issues such as no throttle response or an imposed speed limiter, to allow you only to safly get to a repair shop only. The ECU is another possibility for this issue unfortunatly, the reason I say that is because of the price an ECU runs to replace. Being a sealed unit you will not be able to have a tech savvy repair man “fix it”. Leaving the only option of replacing the entire unit.

Like I said im am by no means an expert, But honestly if the car runs at idle like you say, then it tends to limit the most likely causes of the issues you have.