Oak

I had the secondary air code early on fixed under warranty, I think the culprit was a leaking T or a plastic fitting from the dv's.

MitchB

I will go back in there and clean up the installation. Got a few lines that need to be re-routed to prevent chafing, and I'll zip tie those small lines as well.
Since I didn't find any split lines or loose fittings, I wanted to hurry and drive it to see if the DV valves fixed it. Blowing through the old valves confirmed it.

The happiness of fixing it almost overides how pissed I am about the Tuner shop that tried to f@*k me... Almost.

Thanks for the advice along the way, Kevin.

Kevin

Mitch, I'll fly out "tune your ECU" and install a new air-pump for $3K

JG 996T

This code popped up on me today. Going to check the lines tomorrow.

meach1957

Just bought a 2002 996 C4. Have had 1 week and engine codes P0491 & P0492 have popped up. Does the turbo vacuum system look the same as non-turbo. Trying to trouble shoot myself.

JG 996T

Not sure, but take a look over on renntech.org - there may be info for non-turbo. (you have to join)

PorscheDoc

No, it is fairly different, but since you are throwing both banks, check to see if the pump is actually working.

Other than that, check the vacuum lines or the SAI Valve which clogs just like they did on the 993's.

DrainsWalletsFast

I had my diverter valves replaced and soon had a similar issue and would not make full boost (peaked at 0.7 instead of the usual 0.9 on an X50). It also made a strange noise when you'd get on the power. I too found the problem to be a vacuum line that had come loose. Good luck with your issue.