zpmada

Hi all, I have a 2001 Pathfinder that I am trying to make compliant for a friend with a check engine light. The car originally had a few codes due to the idle control valve. I took the upper intake off, replaced those gaskets and the idle control valve. I also replaced the PCV valve (aftermarket brand) as the old one was blocked. Now I am left with a P1491 code. I am not sure if I had this code before I removed the upper intake manifold, or if it came as a result of removing the upper intake manifold. What can I check to rule out the upper intake manifold? Could a defected PCV valve cause the P1491? (I sure hope not as that valve is burried under the upper intake manifold). Here is what I have done so far, with no success: Replaced Vacuum cut solenoid switch (Genuine Nissan Brand) Replaced Vacuum bypass valve (Dorman Brand) What else is there? I noticed when I removed the hoses on the vacuum cut solenoid switch, it was a little moist with fuel. Is this normal, or do I have to dish out $200 on a new charcoal canister? I'd had to keep throwing money at it without knowing for sure what the problem is. Thank you!

Sorry I should have been more specific. When I took it to Nissan the first time, they did "re-learn" the idle speed. The Check engine light was off. However, the next time I started the car the check engine light came on and P0505 returned.

I recently had an independent mechanic clean the battery terminals after fixing a P1320 code. He said take it to a Nissan dealer to fix the P0505 code. The Nissan dealer charged me $120 to "diagnose" my car, but they didn't look into the P0505 code like I had asked. They just said I need fluid changes, a ball joint and cv boot, repack bearings, brake fluid change, pads, and this will cost $2000. They said for P0505 diagnostic I will have to leave the car 4 hours. They said it is possible the previous mechanic did not disconnect the batter in the right sequence which shorted the computer. Is that even possible? I did not have the P0505 before taking it to the first mechanic. Just the P1320 and an O2 sensor code. The next day I get a call asking me if I want to trade in my car for a new one... crooks. It is possible the previous mechanic did not disconnect the battery cables in the right sequence and fried the PCM/ECM/ECU?? Since the dealer was no help, I bought a chilton manual. I checked the resistance on all terminals for the ISCV and I had ~24-~25ohms. The connector going to the ISCV had power so that seems ok. Next I checked the connectors going to the TPS. The orange one was ~5v (fine according to the chilton manual), but the second gray connector didn't show any voltage reading. Where does the power for this gray connector come from? If I don't have power going to the gray connector on the TPS, will that trigger a P0505? Can I open the ECU up and re-solder the TPS circuit myself? Is there a reputable pathfinder ECU rebuilder? Some guy on ebay is charging $200 to take my ECU, rebuild it and mail it back. Is there a guy with a reputation out there if indeed this is my problem? Thanks