Double Secret Probation

Just had the dreaded CEL come on, local auto parts store ran the code for me and it came back P0491 Secondary Air Injection System Bank 1 -
Understand this relates to the emissions system -

Not too keen on my local dealer - any quick suggestions on troubleshooting? Where to look for loose hoses? I think i'm outside my warranty coverage and can see them charging me a @#$@$#@.

Also noticed my MPG has dropped ~1-2 MPG average/highway - would assume this is related?

Thanks for any advice/info!

ShibbyUTMan

Bump to the top. I have had two instances of this, light comes back after clearing. 2012 A7 69,000 miles.

Vodka G

you probably want someone with a VAG COM to ready the code. The generic OBDII reader doesn't provide details with that P0491 code.

but judging from this....sounds like the secondary air pump or a vacuum issue

ShibbyUTMan

I've done some more digging on the issue, found a few posts on the Q5 forum that seem relevant here too. I just picked my car up from getting fuel pump recalls done and I did confirm with the service writer that here's what's up.

Secondary air injection failure basically. There is a pressure sensor that is part of the air injection on each bank and a spec for it. Basically when the injection pressure gets too high for each bank there is a restriction in the way. The air injection ports are along the bottom of each of the exhaust runners exiting the head and are prone to carbon build up. At some point they will plug shut and you'll get a P0491 and P0492. There IS an extended service action plan at the dealer covering vehicles for if I'm remembering right, 8 years 120,000 miles. In order to have the service plan carried out, you need BOTH codes to be active. Service to remedy this is an engine out service, shoot yourself in the face if you have to do this out of warranty.

adrock20013

ShibbyUTMan,

I just recently had this fixed last week. I had both codes and my car is a 2012 A6 3.0T Quattro - Prestige.

The warranty on this issue has been extended to 10 years/ 120,000 miles. I can VERY solidly confirm that Audi will cover the repair of the P0490 and P0491 codes (both sides) under warranty, regardless of who owns the car. I bought my car used from a used car dealer for a great price and got curious to see if there were any recalls on it. I got online, entered my VIN and found that my car had 3 open recalls.

I did some further research and found that the secondary air system warranty was extended to 10/120,000 and when I told them I had the correct codes, they fixed that as well after verifying.

I basically got an entire new fuel delivery system, new passenger occupancy detection sensor, brand new thermostat, brand new fuel rails and fuel injection seals for free! They also cleared my Service Due light for free as well, even though I told them I'd just deal with it since they charge $45 just to clear the message when you change your own oil....

As for the secondary air system code you have, I can't confirm whether it has to be one or both, but my car has 117,000 miles on it, so I got SUPER lucky to find these recalls and the warranty extension for this issue when I did. Good luck.

John Gaddum

I'm running into the same issue and fear I'll get hit with similar results. I bought a pre-owned 2014 A6 3.0T and getting the P0491. It's been coming on and off but now emissions are due! Where did you go to find recalls and what type of Audi and Age?

murf3319

Purchase my 2012 A6 from used car dealership November 2015. P0491 and P0492 codes started showing up two years ago. Reset and drive for months with zero issues, until 6 months ago and would not reset. Took to Audi Nashville and found out Audi NA has extended this warranty and it helped that codes showed in history going back some time. Warranty covered at no cost to me with approx. 60K miles on vehicle.

Dskvid

So it turned that you have to have both codes going before the recall will work? I have been getting the P0491 but not the P0492. I think I had it once but I always will clear the codes and see if they cannot me back, the P0491 keeps coming back. I got to get out of that habit now that There might be a recall. .

2014_s5_Canada

Hi Murf. I'm in Canada and Audi Canada is denying warranty coverage for this issue. Did you say Audi NA has extended this warranty? Do you have anything you can send me to this effect?
Thanks,
G

2014_s5_Canada

John did you have any luck with warranty coverage for your 2014 A6?

G