While trying to get some dye into the A/C tonight to track down a leak in the system I happened to press down on the large vac line coming from the booster to the UIM and noticed that the high pitched noise I've been hearing for a while now magically stopped. I was able to replicate it by letting it back into normal position and then pressing it down slightly again. When in normal position it whines/whistles.
I've had a lean code for who knows how long and figured it was the egr tube to the LIM. I even replaced the vac tree that snaps into the UIM last week because I had a spare new one laying around from a prev. UIM job thinking that maybe the o-ring on it was bad, but still have the same noise. It's as high pitched as an alternator with a bad field coil, so that's what I figured it was but now I'm thinking this may be my issue and not the egr tube?
And no, I haven't had time to scan it and read live data to see if my LTFT's come back down from 16.4 where they've been. Might have another set of hands press down on the line tomorrow while I read the scanner to see what it says.
and I need to take TB off and clean it. When I put it back I noticed the air intake "tube" actually acts as a lever on the UIM. OOPS - I "upgraded" the LIM about 8 years ago along with a few other fixes/mods and I believe by twisting the tube onto the throttle body I created a leak. FWIW - put the air intake tube onto the the throttle body BEFORE you attach the throttle body to the UIM as I learned the hard way and created a vacuum leak between the UIM and TB.
