2002 Dodge Dakota SXT v6 runs fine until temperature reaches 150 degrees then it chugs backfires stalls until it reaches 200 then it levels out and I'm able to drive it, but once it sits and cools back down under 150 I have to start the process all over again...... the original problem was no bus in the odometer so I changed the camshaft and crankshaft sensors didn't work so I got a new PCM(well new to me) and the truck started right up until hitting 150 degrees..... have changed the timing belt plugs wires, two remanufactured computers all four o2 sensors.... have spent $1,400 on mechanics and parts, they all say there's nothing wrong with my truck.... there is a major leak coming out of the bottom of the catalytic converter on bank 1 could this be my problem any help would be appreciated.

 

3.7 or 3.9?

 

It's a 3.9

 

is your check engine light on now?? if so, what codes are you getting?

 

This has been going on for 3 months so I've been getting a lot of codes the main one is p1391 it showed up on both computers I put in other than that a lot of o2 sensor codes and misfires codes.....

 

p1391 is CPS , I hope you didn't put in a cheap bwd sensor from advanced auto, or any other cheap sensors for that matter, the magnets used in theses cheap sensors are only half as strong as the originals sensor..also, if most of your misfires are coming from bank 1 with your leaking converter on bank 1 then that would be a great starting point to fix that.. you have a California model also ( 4 o2 sensors) did you buy the proper o2 sensors for the correct location, there's a difference between downstream left and downstream right, I have a California model as well and I found this out the hard way...id also get a scan tool and observe you engine temperater as its warming up, your temp sensor might be giving the pcm some funny readings..

 

I have a scan tool and the temperature sensor is working fine I've got four o2 sensors got the factory sensors for that but I got the cheap crankshaft and camshaft sensors from autozone but my mechanic says they're both running at 5 volts and there's nothing wrong with them..... if changing the cat doesn't help I will get a factory crankshaft sensor

 

5 volts is the input voltage to the sensors from the PCM. The output varies - considerably.

CPS and CMP are a great place to start.

 

Get OEM cam and crank, if for no other reason, to make sure you aren't chasing your tail in circles. I see so many bad (and new) aftermarket TPS, cam and crank and coils. It's ridiculous.

 

ok first thing right off. running at 5volts doesnt mean that the sensor is working correctly. second thing. the coolent temp sensor has 2 outputs one for the gauge one for the ECU. the gauge part may be working correctly but the other half not. and watching the temp gauge isnt gonna tell if it bad or not.

there are a lot of other factors playing in effect at the tempatures you are having this issue with. the fuel pump is warming up the intake, manifolds, timing chain, transmission compoints ect. what you need to do is start over from the beginning. ignore what has been fixed and what hasnt. read the code. and diag from there. i find that more people over think and mis diag because there have to much information. (i have been known to do so myself at times) yes the code as a CPS code you need to find out if its for high or low voltage or if a correlation code. most people just read the CPS part and never finish reading the code and waste money.

as for the no bus to the insterment panel that a major issue and needs to be fixed. the commmunication on thses trucks is a major importance bc its a 2 wire system. it need all the computers to agree on the reading or its triggers a MIL. normally the wiring is bad and not the COMPUTER. i have about 6 of the gen 2 computers that have been beat up, in accidents under water. even on fire and they still work just fine.

and the cat will deffently cause issues fix that and soon. that will burn valves and lean out that bank. these motors can take a lot but valves cant.

please let us know and good luck