ARRRRRRGH! More fault codes- Help!

[Steve Cole]

Originally Posted by akdg87

are the o2 sensor harness routed to the correct sides? IE bank one is truly on bank 1.

I will double check this today, along with checking the fuel pressure.

Thanks for the suggestion!

[edgeleycanuck]

I have just recently had my truck wired and fired by a local performance shop. I have only started it maybe 10 times and driven a couple of miles. It is a used 4.8 out of a 2000 pickup. On initial startup it has been running very rich especially when cold, it now is not starting with out some throttle, I have not checked for codes yet, the wiring harness is new as are the oxygen sensors. The mechanic asked me if the intake gaskets have been changed, I bought the engine in a wrecked donor vehicle so I don't know. Long story short he said the truck intake manifolds are known to fail( not sure of which model years), he said the engine draws more air and wants to add fuel.... Anyway I have no idea if my blathering is helpful but just wondering if the possibility of a vacuum leak you mention could be an intake gasket failure?

[Steve Cole]

Originally Posted by Steve Cole

I will double check this today, along with checking the fuel pressure.

Thanks for the suggestion!

I verified that bank 1 connector is on the drivers side as it should be.
I also checked my fuel pressure. When the key is turned to the first position, the fuel pressure goes to 60 for a couple of seconds then drops to 50. When running, it stays steady at 60 psi.

edgeleycanuck:

Thanks for the suggestion, I am willing to try anything at this point. Before I installed the engine, I replaced the intake manifold gasket and tightened/torqued it using the correct tightening/torqueing sequence so I don't think this is the culprit.

Can someone identify all the vacuum hoses I should check?

My configuration is not stock. I am using a LS6 valley cover with a hose running from it to a oil catch can and from the can to the top of the intake manifold. I have the port on the rear of the drivers side valve cover capped off and the port on the front of the passenger side valve cover running to the throttle body. My brake booster hose is too big but I have it cinched down with a hose clamp pretty good until I can come up with a permanent solution

[tbrown5079]

At this point I would find someone with a smoke machine to determine where all the vacuum leaks are and repair them before you replace anything else. I fought the PO171 and PO174 codes until I finally borrowed a smoke machine and found a gasket out of place on the right bank valve cover (the side the donor vehicle was hit on. The stud on the valve cover was even bent). I know this can be very frustrating. Tbrown

[Steve Cole]

Originally Posted by tbrown5079

At this point I would find someone with a smoke machine to determine where all the vacuum leaks are and repair them before you replace anything else. I fought the PO171 and PO174 codes until I finally borrowed a smoke machine and found a gasket out of place on the right bank valve cover (the side the donor vehicle was hit on. The stud on the valve cover was even bent). I know this can be very frustrating. Tbrown

Hey Tbrown, thanks for the suggestion but I seriously do not think it is a vacuum leak. I put a code reader on it with "live data" enabled and watched my fuel trims. When you come off idle and go to about 2000 rpm, the short term fuel trims should get better if your problem is a vacuum leak. My numbers did not change at all. At this point I am thinking it is tied to the other fault codes I am getting (P0053/P0059) O2 heater resistance banks 1&2 sensor 1.

Still looking for ideas!!