LS3 Problems, any help appreciated
LS3 Problems, any help appreciated Just finished an install of a 415ci LS3 into a 07 Trailblazer SS. The motor has ported ls3 heads, mild cam, SLP Longtubes, Fast 102 intake, TPIS throttle body, and PCM4Less CAI. After the engine goes into closed loop the exhaust temps shoot through the roof and it throws a po171 and po174 code and the headers start glowing so bad you can almost see through them. As of now the truck is on a stock timing table at idle and fuel seems to be dead on. We checked everywhere for vaccum leaks, took apart the Fast intake and resealed it, deleted the EVAP solenoid and re ran the PCV and the problem is still there. Anything we could be overlooking? Thanks a lot.
Check to see if all the tubes are blocked of or connected near the TB on the intake. The Pcv and the vaccum connections. Also did you connect the small rear hvac connection in the back of the intake? Are you mafs or SD? You have unmetered air coming in from somewhere.
This happened to me the other day when I added a breather / catch can and forgot to cap off the connection on the intake.! Lol
This happened to me the other day when I added a breather / catch can and forgot to cap off the connection on the intake.! Lol
Using a Fast intake the valley cover bolts to use are the button head Allen wrench type, cause the OEM are too high and are likely keeping the intake from sealing properly. And or check for catalytic converter clogged up. when you find what it was let us know , thanks.
Last edited by CAMSTER; Sep 26, 2012 at 09:17 PM.
