PO491 & PO492

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#1
Please fill out the following to ask a question.

MAKE:Audi
MODEL:Q7
YEAR:2011
MILES:
ENGINE:3.0 SC
DESCRIBE ISSUE....Hey guys...I have a 2011 Audi with the secondary air injection system codes in here...The fuse is good the relay is good and the pump runs...I have checked the lines going from the pump and don't hear any leaks...I reset it a few times and drive it but the codes keep coming back...I am not sure what else to check on this thing....anybody have any ideas what I can try next...Thanks for the help....Jim
 

kev2

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#2
this popped up on quick ck- one TSB for both #s a likely suspect.

SORRY I did not read it - hvn't had coffee and its 15 pages of german BS
 

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nickb2

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#3
Ha, if car drives ok, ignore those codes. More a hassle to remove them with the above TSB. Not something you can jerry rig easily to clean out those ports with your everyday power washer. This is an emission code, but from what I understand, you live in a state with emission testing, does this super charged luxury car need emission testing soon?

In principle, there should be no drive-ability issues when these codes are present.

You could try a few bottles of cataclean or something similar in the tank and drive the wheels off it for a while and do a very through carbon flush with a good solvent for these sensitive engines. It may help disappear those codes prior to emission testing.
 
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nickb2

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#4
Basically you want to attack the carbon buildup in the system which is causing a insufficient flow code on both banks at same time.

I think it would be best to try to inject some solvent in the secondary system prior to the two pumps. Maybe at the secondary air injection solenoid valves. They are prior to the whole system and may have the best ports to use to get the solvent in there and have the best chance of cleaning all the insides that the TSB refers to. My take is that they are gummed up with a shyte load of carbon as most audi and german cousins tend to do. You should see the inside of an oil pan when I do audi with turbos. The carbon build up from the return oil lines is crazy when a turbo fails.

This being a super charged, not so worried about that.

Maybe try running some cataclean or similar straight through to solenoid ports in a concentrated way. https://www.4wheelparts.com/Perform...MIpIv6hrGl1wIVGLjACh2OcA94EAYYASABEgLapPD_BwE
 

BC

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#8
I remember in the days of carburetor a good friend showed me this trick of squirting water into the carb intake with the engine running and while holding the throttle open as to not let the engine die out. The water would dissolve the carbon under heat and pressure fairly quickly. But, I suppose that was back in the days when things were a bit more simpler.