Hey guys, I have just bought an 98 audi quattro A6 with the 2.8 engine. I have a few check engine codes coming up.

- P1136/P1138
- P1476

I noticed there was a sucking noise coming from under the car at the rear end, I crawled under the drivers side just behind the rear tire. Listened and looked and noticed there was a line broken. I put my finger over the line and feel vacuum from it. At the same time while I put my finger over the hole and the engine will idle down. The line runs from towards the front of the vehicle right near the rear wheel, then it goes up into the body somewhere out of sight. Not sure what it is for or if it is the cause of he faults. I slid a rubber hose over each end to connect the broken ends together, engine idles down and now im just waiting to see if anything pops up again. Hope someone has some pointers for me, Thanks in advance.

 

I would check the purge control valve , could be stuck open causing fuel mixture to be off & vacuum applied to the evap system when it is not supposed to. Should be a 2 wire/2 hose valve on top of the air cleaner. The engine side of the valve should hold vacuum. If it does not it is bad.

 

Well turns out that line that was broken solved both fuel banks being lean. Thanks for the info though.