I'm new to the forum and I have all sorts of problems to fix. The original problem was I could start the truck up. Ran fine drive down the road a couple miles. Out of no where truck would stall out and die. But I could start it back up and it would be ok during my 10 mile trip home from work. I had a code for both o2 sensors for a wile but we checked the fuel pressure and it would flicker on the gage when it started to run bad so we thought it was time for fuel pump(97,000 miles). We change the pump. Now this thing runs worse. So we get two new o2 sensors.(there is only 2 on this truck. One pre cat one post.) put the two new sensors in clear the codes no better. The code comes back for the pre cat o2 sensor. It says the voltage is too high. Should be at 2.5 volts and it gets above 4 volts. So we check for breaks in the wiring. Check grounds. Load test wire. No problems. So then I look around and hear that you should only use the factory o2 sensors so we replace the front one that's triping codes with a factory o2 sensor. Clear the codes runs great for 30 miles park it. Starting back up later that day, idles like **** and it has a lean code now on pre cat o2. I did find out I can computer by unhooking the battery and cycling the key 3 times. This makes the Computer drain it's battery back up, I was told and it puts the setting back to factory. Seems to work for a day then back to normal. I'm worried it's the computer. I don't think it's the cat. Any ideas?

 

Well im having some of the same problems, and i was going to start by saying cat since youve replaced the o2 sensors, but im not real sure. Im getting P0171 The to lean code and it runs like crap also but the one time it stalled idiling i started it back up and reved it up and i had all kinds black stuff come out of my tailpipe that hasnt happened to you has it?

 

I don't think mine has blown any black smoke out. I forgot to say I did put a new set of plugs in it too. Still the same. I would think the cat but it runs fine when I reset it. I would think the cat would make it run bad no matter what.

 

Yeah hopefuly not PCM

 

Did you evrer get a response/Answer to this, I have the exact same issue.

 

Did you try throttle body cleaning?

 

The main problem seemed to be the o2 sencers telling the truck it was running lean. After trying multiple o2 sencers and different brands then trying factory replacments from the dealer. Still no luck. However the the truck had almost 100,000 on it so it was about time for them to be replaced. New plugs didn't help. We re-flashed the computer and it was fixed after that. Drove it a couple months with no problems.