Just two sensors, one upstream, one downstream. (Cat)

 

Well drove it to work and had to turn around because it started to stumble and lose power. Sometimes dies at stop light. Idle is erratic. Only way it would go is if i floored it. Don't know if fuel is being cut off for some reason or what. I talked to the mechanic that did the most work on it and he said something is flooding the engine. When he put in new o2's they would burn up within 20 min. He would pull them out and they are full of soot. I ran the theory of the o2 circuit being bad in the pcm and he thought it might be possible. He also that the pcm's are vehicle specific so i can not get one out of the junk yard. My experience in the past with those type of symptoms is vacuum leak. Any other thoughts. If the lakes weren't frozen i would just drive it in one. Thanks.

 

I don't think i mentioned that it is the 4.7 motor. Don't know if that makes any difference.

 

The PCM is only vehicle specific as far as the engine size and VIN. You can take a PCM out of a junkyard but you have to get it flashed with your VIN in order to show accurate mileage and get it smogged I think. I don't think that is your problem though. Without being there to diagnose it this one is pretty tough. Soot definitely shows overfueling or an inability to burn the fuel. Did you change the wires, cap, and rotor? How about the air filter?

Fuel/air/spark just remember driveability issues usually result from one of these being off.

 

4.7 genious hehe

 

This motor don't have cap, rotor or plug wires. The ignition coil for each cylinder is right on the plug. I have done some more web surfing and got some other ideas to try. I am getting a coolant temp sensor to start with. I am also going to check engine vacuum which is 13in at idle. Check pvc system. Can you tell me what examining freeze frame associated with a particular code means?

 

The 4.7 came in a 1999?

 

DOH I lost track of the engine size we are talking about here!!!

No Neo the 4.7 replaced the 5.2 in 00'

I am thinking freeze frame would be referring to using a lab scope and recording information on it.

 

Holly s#!&. I just realized i put the wrong freakin year up on this thread. My 1ton is a 99. Some other b#%&!. Sorry guys it's a 2000. Thanks Neo. I would have kept on using the wrong year here.

 

I was wondering where Neo got the wrong info.