2005 tahoe blackbear tune and other issues

[Ryanz71hoe]

Received an email back from blackbear telling me i have a pretty sizable vacuum leak because my throttle % is at about 2% average, and most tahoes with that engine run at about 5-6% throttle to maintain idle, and in addition i have a dead O2 sensor, passenger side upstream.

Before i even went through the process with blackbear, i was already tracing down the infamous "rough idling" and it drove me crazy because the truck basically picked and chose when it wanted to do it. We found no vacuum leak, after checking on a few different occasions. Anyways, we came to the conclusion the problem was the fuel pressure regulator (built into the fuel pump). Now i'm running about 1.2 % throttle after changing the fuel pump (changed with AC Delco). do i have to relearn the fuel pump somehow? how do i get my throttle back up if i cant find a vacuum leak? maybe there is one but me and the 2 other mechanics that checked couldn't see it?

i sent the new data to blackbear, but figured i check on here too while i have time on a sunday. before anyone responds, here's what i have already done to the engine -

Replaced MAF Sensor (OE)
Replaced throttle body and added throttle body spacer (both JET Powr-Flo)
Replaced fuel pump, filter and pressure control built in
new AC Delco plugs (iridium ADO-41-110) and 10.4 MM Taylor wires
hypertech 180 thermostat
Powermaster street alternator (165 amp)
yellow top battery
both AC Delco Knock sensors and chevy performance wiring harness
new manifolds (both sides)
Corsa Exhaust system
Spectre performance air intake kit

 

[Rocket Man]

Sounds like an intake manifold leak which can be hard to find until you actually pull the manifold and look at the gaskets. I don’t care what everybody says about spraying with brake cleaner and listening for a change or using a smoke machine. I did both and found nothing until I pulled my supercharger manifold and saw the gaskets. Or it could be a leak in that Spectre CAI. Make sure the couplers are on far enough and all clamps are tight.

 

[iamdub]

Did you change the knock sensors after or before BlackBear informed you of your leak?

 

[Rocket Man]

Did you change the knock sensors after or before BlackBear informed you of your leak?

Good question since the manifold had to come off at one point.