ToadMan8

(Not sure if this is related, but I'll start here) - 2004 A6 2.7t 6 speed

-Around August, several thousand miles ago, replaced cam cover seals using the sneaky top-down method. Damn certain timing did not slip.
-Two months and 800 miles ago hard-acceleration would occasionally cause period of very rough idle, almost complete loss of power. Typically clears up while driving, and always cleared up after fully cooling.
-Last night, very rough idle, no acceleration, stalled pulling into driveway. Pulled codes, cleared them, restart, very rough idle, absolutely no acceleration even in neutral, pulled the exact same codes as follows::

16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 -
16685 - Cylinder 1
P0301 - 35-10 - Misfire Detected - Intermittent
16688 - Cylinder 4
P0304 - 35-00 - Misfire Detected
16690 - Cylinder 6
P0306 - 35-00 - Misfire Detected
16487 - Mass Air Flow Sensor (G70)
P0103 - 35-10 - Signal too High - Intermittent
17965 - Charge Pressure Control
P1557 - 35-10 - Positive Deviation - Intermittent

(Sorry about the formatting, stupid computer in the garage won't get on the network, so I had to retype it.)

I guess my inclination is to replace the MAF sensor after confirming that there are no obvious vac line or air piping issues. I'd be surprised if it was a small leak causing the issue based on the fact that the car had been running absolutely beautifully for hundreds of miles, then has a coulpe minutes of terribly rough performance, then back to perfect. But, when it comes down to it, I don't know **** about ****.

Thoughts?

Thanks so much

ToadMan8

Sometimes it's the simple things...

While disconnecting the MAF sensor for troubleshooting purposes, I noticed that the neighboring hose clamp was improperly installed. Pressurized air was causing the pipe to blow apart, leaking air. It was difficult to notice when the car wasn't being rev'd, however, because the pipe comes back together by itself when it's not pressurized.

So, good news is that it's working perfectly again, after months of worrying about it. Bad news is that, as I feared, I'm a dumb ***.