Car threw a check engine light scanned the codes and had a mis fire on cyl 1,2,3 and a system too lean code. So I checked for vacuum leaks and found a split in one of the lines on the backside of the motor. It looks like it runs down to the top of where the oil filter screws in. Im needing to know which line this is so I can replace it. Here is the best pic I could get of it.



Any help would be appreciated.

 

seems you've located one problem... remove the line and take it in for a replacement. some lines are common that you often can get a lower cost replacement...

I had s similar prob on my 2003 A4 those hoses are a PITA to get to, but they are replaceable.

use good hose clamps...

hard to see the hose on your photo. ...might also want to check for breaks on the check valves as they get pretty hot behind the engine as well.

Be careful removing hoses from those small check valves as the ones that were subject to high temps have become brittle and tend to break at the base of the nipple. if necessary, remove the entire assembly, re-construct the hose/valve then re install (it will be less stress on the lower back).

 

http://www.audizine.com/forum/showth...simplification
here is a diagram of the vac system to give u a better idea of what tube it is. Hope it helps.

 

Ok so I found out that it connects to I think its the crankcase breather hose. It T's off that and runs down the block onto the top of the oil filter. Anybody got a guess?

 

yup, its a breather hose that breaks all the time. It did on my 04 and was the worst to replace. It's several hoses that you need to assemble and heat in order for the hoses to connect. Ended up buying all the parts and bringing it to local shop to replace.