Hi guys,

I'm a bit of a novice with VAG-COM, so would appreciate any insights on (what I assume is) a leak I'm trying to track down. CEL popped about a month ago after 5 hours of highway driving...it started as "intermittent" designation, but now it's just a full-time "system too lean" code. I've got 2 sets of block 32 data below (most recent one from tonight, the other from a few weeks ago)...looks like it's gotten worse as I've tried to fix shit.


Actions and observations;
1) MAF is 1 year old. My first step was cleaning the MAF sensor, but the code came back
2) Fixed some exhaust pipe leaks (flex pipe and muffler), but code came back
3) Replaced a small amount of suspect vacuum line where my boost gauge tapped in, but the code came back
4) Boost holds steady at 9psi (I'm stock). When the code first came on, I noticed one or two instances of boost spiking on the highway (15-20psi) but that hasn't happened since.
5) Vacuum at idle has been a steady 20 In.Hg...but today, I noticed it chilling at 16. No bueno.
6) On startup, engine bogs at idle a liiiitle while the secondary air pump is on (idle at 1200-ish rpm, vacuum at 10In.Hg), but the rpm needle barely moves...once warm, the engine idles steadily around 900rpm

NEXT STEPS and QUESTIONS:
1) This weekend I'm going to formally hunt for leaks. Spraying carb cleaner, then trying a DIY pressure test. Looks like my hoses are all original. I've got new check-valves enroute and vacuum hose (I hear the PCV valve under the intake is kind of a PITA). Any spots in particular to look at based on the info below? Suction jet pump?

2) What other blocks should I scan/log for a more useful diagnosis? It's not easy for me to do WOT redline pulls (yay, city living) but I can try. MAF is block 002, right? Block 003 for AFR?

3) I've got a roadtrip coming up next weekend...like, 12 hours of highway driving. Would making the trip while running lean potentially cause some real damage, or are we just talking about shitting gas mileage? Guessing the CAT and O2 sensors won't like it...



17544 - Fuel Trim: Bank 1 (Add)
P1136 - 35-00 - System too Lean
Mileage: 83179

Group 032: Lambda Control (Mixture Adaptation)
9.0 % Adaptation (Idle) Bank 1 Sensor 1
3.9 % Adaptation (Partial) Bank 1 Sensor 1



17544 - Fuel Trim: Bank 1 (Add)
P1136 - 35-10 - System too Lean - Intermittent
Mileage: 83012

Group 032: Lambda Control (Mixture Adaptation)
5.1 % Adaptation (Idle) Bank 1 Sensor 1
0.8 % Adaptation (Partial) Bank 1 Sensor 1