I don't think he knows where its coming from.

 

its coming from the cat area which kinda sounded like the back of the engine at first.. i listened today with a tube and along screwdriver.. i still cant pinpoint it, butthe camchain area is pretty quiet, besides i doesn't do it on idle. i've personally always thought it was coming from there but when cam chain tensioner was mentioned so much before i leaned towards that. and since i'm throwin the cat code now (16806 p0422). i checked the weld at the turbo for leaks, couldn't feel any. the sound seems like its coming at the end of the cat near the post 02 sensor. i cant get back there to feel around for leaks. also there i can't really hear it when the engine is cold.. took about 5-10 miles of driveing before it was really loud again.. i can't hear it out the drivers side window very well, but easily out the passengers window.. that also leads me to believe its the cat. here is a quick vid i took before the batteries died... i'll get a better one up later if you guys want.

http://uk.youtube.com/watch?v=JVMHX-OlLJQ

 

Wouldn't a blown diverter valve make an exhaust tick on decel? Stock DVs are plastic. It's easy to get to: remove belly pan. It's black, size of your fist, below and in front of air cleaner box and has 2 1" diameter hoses going into it.

--Larry

 

put in new dv710nabout a week ago..

 

That sounds like a rattling cat to me, un-bolt the cat then run the motor.

 

threw another cel today.. got the 16806 p0422 and also got this one

16825 EVAP Emissions Control Sys: Incorrect Flow
P0441 - 35-10 - - - Intermittent

also, whats the best way to get at the lower bolt at the back end of the cat.

 

Its a pain in the ***. You gotta get it from underneath the car with a 2 ft socketextention, just like the other 2 bolts. Here is a taste of what youd be doing:
http://forums.audiworld.com/a4/msgs/2479672.phtml