CEL P0491 /P0492

[993turbo]

Got the CEL today. P0491 / P0492. VCDS readout: SAI system insuffcient flow bank 1 / 2

any ideas?

Cheers.

[C6NVS]

This might help as a start:
http://www.audizine.com/forum/showthrea ... leshooting

Also, check the connectors into the airbox on both sides. These can sometimes split at the airbox connection and cause an air leak in the system, setting off the codes.

[993turbo]

Cheers, I did delete the codes, and they did not come back yet....

Will check the connectors etc.. Cheers for the link.

[perthwaRS6]

Hi 993turbo,

I had same SAI code- see pic 1.

Under warranty, engine pulled for SAI replacement, along with clean up of electrical connectors.- see pic 2.

From trolling Audizine, poor electrical connections are a significant cause of error codes.

After the warranty repair, Audi Diagnostic did not show any further error codes.

Strangely , the beast is running a lot stronger since the warranty work. Cant see why as SAI does not influence turbos/boost etc (?). Maybe some of the other "clean up " work listed improved performance?

Unfortunately, almost straight away now throwing up VCDS error codes again and have since owned the beast on bank 1 -p2261 Boost pressure control valve (N249) mechanical malfunction and bank- 2 p3084 -turbocharger bypass valve- mechanical malfunction.

Cannot understand why these two VCDS errors keep coming back again as no discernible decrease in performance feel of the beast. Possibly a very small boost leak?

Will have to learn how to run my VCDS real time data logger function while driving to see what is happening between called for boost and actual boost.

Off to Audi dealer for a scan to see if they can replicate the VCDS errors p2261 and p3084. They look for but seem to not be able to see these errors on their scans so cannot repair under warranty.

Just keep an eye on your scans for more SAI codes.

just my two cents worth.
cheers,
john

[Erwan35]

So what seems to be the problem? I am having same codes. Please help. Audi rs6 c6