CartoonDog

I was getting a CEL with a 17544/P1136 - Fuel Trim: Bank 1 (Add): System too Lean on the VAG. This error can be anything from a bad MAF, O2 Sensor, or a leak.

I discounted the MAF after using the VAG and running the car to MAX RPM and using the info from Ross-Tech as a rule of thumb. I figured that my O2 was good because I wasn't using excessive fuel as usually would be the case. So I was left with the unenviable task of finding a vacuum leak.

Finding it ended up being far easier than I thought. After a tip from a mechanic - with the engine running, I used a can of brake cleaner with the straw attached and sprayed many of those inaccessible vacuum hoses. (Do this in a well ventilated area as the fumes will knock you on your can, preferably outside with a fire extinguisher handy) When I sprayed the area with the leak, the car would idle slightly faster. This took about 10min and half a can of brake cleaner to find.

Now that I had an idea where to look, I started unbolting... Under the intake manifold there is a well documented rats nest of vacuum hoses. Mine was the odd hose that is covered in some brittle material and runs from the bottom of the intake manifold to the Fuel pressure regulator. It was completely snapped off the bottom of the intake. Very odd indeed, but a simple fix.

Now that the intake is off, I am taking this time to put on the EVO Phenolic spacer.

The yellow circle below shows the remainder of the hose that snapped off. There are hoses in the background that make it a little confusing.
<center><img src="http://pictureposter.audiworld.com/38888/img_0942.jpg"></center>

The yellow circle below shows where the hose ends up... the fuel pressure regulator, I have the hose half off in the pic.

<center><img src="http://pictureposter.audiworld.com/38888/img_0947.jpg"></center>

JohnLZ7W

Glad you found it, FPR line is a common one to fail early

RoberTT-WWCD

<img src="http://images20.fotki.com/v330/photos/5/58883/3840174/Intakesideconnection-vi.jpg">

Bought a section of silicon hose from ECS Tuning. working fine since.<ul><li><a href="http://public.fotki.com/RoberTT/maintenance/fpr_vacuum_hose/">Clicky</a></li></ul>

kodeTT

from the engine. when i pinched mine to take it off...it literally crumbled into rubber dust.

i'd say replace any cloth covered hoses under the hood.

OldSchool AG

in my garage. =)

ClarkSJ

I understand the new OEM hoses are a better material, but replacing all of them with silicone is a good idea.

ClarkSJ

You may want to check PCV system for leaks/torn hoses while you're in there

heinzboy57

my hose is worn, but still intact..i'd change it just as a precaution, but i can't seem to get that clamp off since it's in a tight angle, and it's clamped on tight.

i worry the nipple will break before the clamp does..

JohnLZ7W

Dremel or some snips, it's hard to get to but the clamp should give before the nipple

heinzboy57

thanks..i'll try the snips again.