Hey guys,

was looking at my buddy's 2002 3.0 a4 quattro today. First, he's throwing the P0421 code - warm up catalyst below threshold bank 1. I did a bit of looking around here and it seems unlear what actually fixed the problem (replacing the primary O2, secondary O2, the cat itself or vacuum lines). Without just replacing one thing at a time, is there any way to narrow down the list??

Secondly, while pulling some things apart and actually locating to O2 sensors (these cars are a bitch to work on) i manage to break a vacuum line at the front of the motor. Problem is, I cant figue out where in the hell it broke off from.

This is the best pic I could get as it was dark out by then:



This is right at the top front of the motor. No clue where the ~3" hose on the right side is supposed to connect to. I couldnt find a vacuum diagram for the V6, only the 1.8 T. A diagram I found for an older V6 shows that this hooks to a vacuum reservoir???

Any help would be greatly appreciated

 

as for the vac line not to sure excatly where it goes. ill have to go look at the engine to see if i can trace it. As for the p0241 code. Its your cats o2 sensor that is bad. Or u cats could be bad.

 

thanks for the reply pa4ul. I was trying to see if there was a way to determine which was the problem before just replacing and hoping.

As for the vacuum line, I got that sorted it. It went to the hard plastic line that ran behind the belts to the bottom of the motor. I just couldnt see it because it broke off about half way down inside. A vacuum diagram I found showed that this ran straight to a vacuum manifold, but when I followed the line it seemed to run up and out of the engine bay, into the wheel well and finally into the passenger compartment. I just left most of the hard line and redid the top half with a soft line. Since most of the lines under there were in pretty bad shape, just want ahead and replaced them all.

 

okay aweseome also all that gunk in the pic is related to your ps. do u tend to have to refill your ps alot?

 

I think i've topped it off twice in 14k miles. Good to know the reason. Any fixes to stop that?

 

http://www.audizine.com/forum/showth...r+steering+fix