Getting p0491 and p0492 on cold starts

[psychodiver]

Hey did anybody experienced this? Im getting a CEL with codes P0491 and 492 only when it starts to get cold outside, didnt have any trouble this summer, it did it last winter and now came back.. weather is between 0 an - 5 celsius right now in canada

Model B8 S4 2010 man

Thank

[TexasDfwS4]

Check all the air lines.

[stereojorge]

Hey did anybody experienced this? Im getting a CEL with codes P0491 and 492 only when it starts to get cold outside, didnt have any trouble this summer, it did it last winter and now came back.. weather is between 0 an - 5 celsius right now in canada

Model B8 S4 2010 man

Thank

I have been getting them also. My Audi technician buddy said it could be the SAI pump going, it tends to happen in our cars. He said it only runs during the first 90 seconds of the car starting for emissions purposes, so even though you get a CEL, just clear it and move on. I haven't seen it for a few weeks now, but it was happening every few days. I'll keep posted.

[RudyH]

This just happened to me too - let me know what you come up with? I m going to be making an appointment myself

I thought it was from carbon build up, however didn't do it all spring / summer / fall but started when the temperature severely dropped.

[RudyH]

Not sure if it will go anywhere...but yes same codes as what others were getting for carbon build-up, however it never tossed a code until the temperature dropped to -14 C. This morning when I started up the car I heard a loud buzzing noise coming from the driver side rear after popping the hood.

Doing some searching, personally I might be ok in that I don't need to do the carbon clean-up (TD1'd after my warranty, found out late about the letter that came out from Audi grrrrr), but might just need a SAI rebuild / replacement = aftermarket warranty

OP, not sure if you have any additional information besides codes pulled?