For starters I bought this truck this summer and this is the first time I have been able to come home during the week to get it in my name. Im in the military and am on pass, I hope I can fix it by Thursday.

I was about 100 miles into my trip from VA to OH, its about a 360 mile trip. It started missing and popping bad. If I mash the gas and get the rpm's up it is fine but as soon as it shifts and gets to lower rpm it starts again. If I shut it off and let it sit for a few mins it might go a mile or 10 but then it starts up again.

I just changed the plenum plate a couple weeks ago. I put 2-3 hundred miles on it after doing it and it was just fine. I really need some help figuring this out. Anybody ever have this happen to them or heard of this? Any help would be great. Thank you very much!!

 

Unplug the front O2 sensor, and see if it doesn't run any better. It will set a code though.

 

It was throwing the front o2 sensor code. It was still driving fine though. It only seems to do it when it gets warmed up

 

Exactly, it doesn't pay attention to the front O2 until coolant temp is over 108 degrees, AND the timer from start has expired. (about two minutes.) You have all the signs of a failed/lying O2 sensor.

 

Ok thank you, Ill go try that now and get back with ya

 

I took out and went on a little trip. It didnt do it but I dont know if its fixed. I drove it to the title office today and it didnt do it on the way there. Im gonna drive it to the parts store and see. Im an idiot and hit it when I gutted the cat and smashed up the end of the one that was in there. What happens if you drive with it unpluged?

 

You will get a CEL.. Do the non fouler on your downstream 02 sensor and replace the up stream sensor..

 

If it got hit, it needs to be replaced.

With it unplugged, the engine will always run in open loop, (which tends to be a little rich) and the CEL will stay on, your gas mileage will suffer a bit... aside from that, no problems.

 

Ok that seemed to fix the big problem. Thank you for the info! I noticed driving this morning, when I go to pull out of an intersection or something that is has a hesitation, it kinda falls on its face then picks right back up like nothing is wrong. Any ideas?

 

did you disconnect the battery for awhile after replacing the o2 sensor? It may be relearning.