2008 CGTS - P1094, P1081 after MAF replacement - help?
 

Throwing this out there for a friend of mine who owns a small shop. Took in a 2008 Cayenne GTS with what looked like a faulty MAF.

Replaced both MAFs, reset codes, short test drive, and the codes came back: P1094 and P1081.

Google returns a few threads on 6speed, etc. with this same problem/symptoms but no resolutions. He's verified there aren't any vac leaks, all the hoses look good, no cracks, etc.

Any ideas?

I can't find anything on P1081, not even in Alldata.

I will guess twice.
Bank 2 sensor 1 , o2
Check fuel rail pressure against specs

I have the same problem, cleaned MAFs with MAF cleaner and codes still reappeared. Replaced the MAF sensors and errors again reappeared.

Any updates?

Nope. Couldn't get it sorted. Got a temporary "pass" on the emissions since the customer spent above a certain $$ amount trying to get it fixed.

Car came back. Buddy took another crack at poking around.

Disassembled the intake tubing and found the TB looked to have some gunk in it. Removed the TB and cleaned it thoroughly. Test drove the car a good 10 miles, CEL didn't come back on (used to come back on instantly). So far, so good!

I had the MAF system replaced on my 2010 C4S Cab manual. I had an uneven idle and and the car would stall sometimes when taking my foot off the gas with the clutch depressed, and then it threw a P1094 code. I took the car to my independent Porsche mechanic. Initially he thought the sensor was bad, since he couldn't find any pressure leaks, but the sensor checked out fine. Then he heard a clicking sound from the throttle body. So he did a throttle body adaptation, and this fixed the problem. Smooth idle, no stalling, no P1094 codes.

Rocky what is a throttle body adaptation? I have these same two codes on my '10 GTS. Threw away the K&Ns that came with it, put proper Mann filters in, cleaned everything, put new MAFs in and CEL and codes reappeared. Interestingly, I drove about 20 miles with no CEL/codes after installation and Durametric clearing but as soon as I turned PSM off, CEL came back on. Clearing again, they come on quickly.

52121, the throttle plate was gunky, cleaned it with acetone but I think I have to remove it and clean it thoroughly.

Notably, truck idles and runs great, but clearly something is wrong and I need to get it inspected.