Hi everbody! I am sure you are smarter than me about this.Popped a check engine light,and went to dealer A.They put it out and said it's going to cost if we have to dig deeper, let's just see if it comes back on.
2 weeks, light back on.So I take it to the local Audi Guru Independent shop.They say it is going to get expensive if we go deeper, lets turn it off, and see if it comes back.
2 weeks, light back on.Take it to the other longer lived dealer B in town.
They say 67870 P1423,P1411 For secondary air B1-B2 and P0117 coolant temp sensor circuit low are stored in ECU.They replaced the tempsender, seal, and a 032-121-142 spring. And turned off the light.Told me the air valve may clean up on it's own,(or fail).
That was July 21, 2010.
Check engine light is back on again,now.Any ideas as to what is going on, is this par? Thanks VERY much.
Oh yeah 2004 A6 Quattro 3.0

 

you need to find what the code is that has returned since they replaced the coolant sensor more than likely it is the secondary air that is still giving you trouble. since your codes were for both bank1 and bank2 more than likely you have an issue with the secondary air pump or the line going from it to the combo valves. The pump is located on top of the engine towards the rear right there is about a 1 inch hose that comes off of it and goes to the combo valves which are located on the back side of the head one on each side of the engine. these pumps failing are pretty common do a little searching on here and you will find lots of reading and pics.

 

I had the same secondary airflow issue for both banks and it turned out I had a huge hole in that 1" hose at the end. Got 116k on the pump and still working fine.
Just check when you start the engine (cold) if you hear the secondary air pump for about 30 seconds. That will tell you if you need to look for a pump issue or the hose.

 

I started a new job, and have been in training.I did take off the top covers and had a look at the hose,(looks great), and did not have time for much else.
It rained yesterday, and I went out to leave, and the light was out.
Is thwere a relay, and could there be an electrical problem,(moisture/corrosion),that could be causing an intermittent light?
We are super dry here.If there is a fuse/relay, is there a picture of where?
I tried searching this site for secondary air pump, and it would not show it.
Thank You very much for your replies,and help.

 

replace all of your vacuum lines secondary air works on vacuum.

Electric also but the vac lines get brittle.

ecstunning has the braided oem style.
the line is cheap do one at a time on a Sat morning you'll be done in an hour

The larger line you can get from advance or any 1/2 way decent parts store.

Get used to that CEL being on Audi owner!
Also get used to Audi techs not being able to repiar your car!

You need a VAG-COM $200 from ross-tech.com

Also a bentley manual from bentleypublishers.com

Have you replaced the timing belt/waterpump/rollers Yet?