Hello i have a 01 pontiac montana 4.3L V6 and the check engine light is on... The problem im having is when im driving down the highway at 55mph+ my van bucks real bad and when i come to a stop light the RPMs go up and down and it stalls on me. I went to Auto zone and they put it on there machine and its showing codes P0341, P0336, P0405.. I changed the crankshaft sensor and the cam sensor and the fuel filter and it was still doing the same thing. Today i changed the plugs and wires and cleaned the throttle body real good and also changed all 3 coils and still doing the same thing. PLEASE someone help me out here im all out of ideas of what the problem could be. Any help would GREATLY be appreciated.

Thanks
Cazic

 

All three of those codes to me, point to the powertrain control module. I cannot believe that the cam, crank position sensor, and egr valve could be related in any other way. The egr valve code probably is a result of the other.

 

P0405 is the EGR valve. You didn't say if you replaced it or not. Before you replace anything else, check the wiring and the connectors to all of these things to see if there are any broken or shorted wires.

 

Welcome to the forum.

Moved to this section to get more notice.

 

Its a 3.4L not a 4.3 like i posted before....

I havent changed the EGR valve i will check those wires out thanks for the info its very much appreciated

Also i sure hope its not the Powertrain Control Module i did try to reset it by removing the negative battery terminal but that didnt help at all... Please if you think of anything else it could be please let me know ASAP... Thanks again for all your help