Bill91

Ok, I think I finally figured it all out. first things first I need to get a different mechanic, because I had him check it out before I started to fix it myself and he said that he checked everything and could not figure out what was going on. to get right to the point, all I needed to do was take my mass air flow sensor off clean it thoroughly with a full can of mass air flow sensor cleaner, reset my air intake tube so it was properly connected with no leaks and I had an issue with my air filter box not sealing properly which was allowing dust to get past the filter and dirty up my mass air flow sensor horribly. my Pathfinder is running like brand new now! and for the record my mechanic is retarded!

ok, looks like I didn't get away with nothing. ran good for a few days and then right back to poo. ordering a new EVAP canister. I'll do it on the road test for a few days and post the results

I also replace the coolant sensor. Not the one that goes to the gauge but the one that goes to the CPU its got a bigger plug on it and it communicates the temperature to the CPU / motor computer thingy under the seat . if the temperature sender is not sending a signal to the CPU to let it know that the motor is warmed up the motor will stay onn "warm up mode" thinking that it's cold and cause the vehicle to run extra extra rich / really bad exhaust fumes.

Check your fuel vapor canister next to the air cleaner box. there's a cap on the bottom that can easily get popped off and you won't even notice it. That's what was causing my truck to idle down low and stall at lights because with the bottom cap loose it creates a vacuum shortage and confuses the motor. on a bright note, the cap will very easily snap back into place if you take the canister loose and take it out and look at it, it's fairly easy to snap it back into place. but it's also very easy to pop it back off again when you're trying to take off the air air intake from the throttle body and jerking around with the vacuum lines