01 Monte Carlo misses under load

[CMNCHE]

Im sorta baffled. Im used to working on Mopars and I can't seem to find the cause of this. My GF has an 01 Monte Carlo SS with a 3.8 V6. It runs fine at idle and up to about 50 mph, but above that or if you try to punch it below that it just falls on its face. I have a GM scan tool and its showing me missfires on mostly all the cyls when this happens. I know the problem is a multiple cyl missfire, but I cant pinpoint the cause. I have replaced the plugs and wires, fuel pump and filter, and cleaned the fuel rail and injectors. Is it possible the crank sensor could cause the timimg to be out under load? I am just about out of ideas?

 

[summitlt]

My buddies has the same problem with the same car. Does her temp guage work correctly all the time? His doesnt and i found a bad Coolant Temp Sensor, wasnt coming out of closed loop running rich all the time.

If thats the problem good luck replacing it.

 

[CMNCHE]

Actually the problem was the cat. converter. There is a TSB for it and it was replaced for free, but her temp gauge does act up every now and then so the sensor probably needs replaced. I assume its tricky to get at?