CEL After Coils Replaced + Hissing

[BonesNTX]

1) I just got my Coils replaced via recall, just prior the CEL came on.
I have now driven for 2 days and about 150 miles and CEL is still on.

2) For the past 6-8 weeks I have a pretty loud hissing sound from engine bay. It sounds like it is coming from the firewall area and toward center. I have looked at the vaccum lines, moved them around but the sound remains the same. It only does this after warm-up.
Kind of resembles a stuck open EGR on a past vehicle I used to have.
MPG remains good.
I am concerned this will manifest a big problem in the middle of nowhere.

I do not have a VAG Com but hoping to get with fellow member who does soon and see what is up. I would like to get going on repair now but I have no clue what this could be?

Any ideas appreciated....Thanks

[BonesNTX]

Ooooops....Of course this is a 2005 V8.

[wvicary]

Could be a damaged vacuum pipe as they are easy to break when service work is being done. Return to the dealer that replaced the coils.

[BonesNTX]

Vacuum Pipe...Where is that located? Just at Firewall center? Servicable by me? That area looks impossible to access except for top.

I have had this loud hissing/humming sound for about 5-7 weeks prior to dealer exchanging coils so they are probably clear THIS Time. I don't do dealer service anyway but...you know...recall this time.

Thanks for the reply

[wvicary]

There are many plastic vacuum lines on the engine and the break might not be obvious at first glance. I recommend finding a indie garage that is familiar with Touaregs and has a smoke machine to test for any leaks. What codes are present?

[BonesNTX]

Originally Posted by BonesNTX

1)...
I do not have a VAG Com but hoping...?

Any ideas appreciated....Thanks

Thanks

[BonesNTX]

Checked with OBDII = No Code

[wvicary]

Clean the throttle body and reset the adaption values.

[BonesNTX]

Originally Posted by wvicary

Clean the throttle body and reset the adaption values.

OK...how?

Are you talking about the "IV Drip" stuff that car repair shops put in.? Takes about 30 minutes of drip while engine runs?

OR...NO, this is not what you mean?

Thanks

[wvicary]

Not familiar with the IV drip but stop in at your local auto parts store and purchase some aerosol carb cleaner, remove the ducting and careful clean the throttle body. It's the gap between the throttle plate and housing that gets gummed up from crankcase fumes. You can open the plate with your fingers easily and wipe out the black build up that could be causing your problem. VAGCOM is the best way to reset the adaption values.