I had similar problems until I changed out the FRONT O2'S.

 

Oddly - I also had almost the exact same issue - and it required new wires. The "soapy water" spray in the dark identified shorts through the wires to the block, randomly generating the misfire codes as well as O2 codes.
New wires and plugs and a little dielectric grease - back to 15+or- MPG and runs well.

I would check the wires for shorts. In case your unfamiliar with the procedure - spray a mist of soapy water solution on the wires and start the truck (needs to be fairly dark) and look for sparks shorting to the block. Some of mine were at the firewall, others further down the wires towards the block itself.

Good luck!

And - Thanks to you, my AC is working again - and the my windows no longer rattle or stop! I appreciate the switch you sent as well as the window rollers. Great solution.
S/F

 

Dropped in the new fuel pressure regulator today and my engine is as smooth as a babies bottom. Problem fixxed. Just have to say a few things to the !@#hole Geek_IM. It is funny how so many people dropped the ball on this problem. You say I lead people in the wrong direction? Look at how many possible fix suggestions were dropped my way. If i had taken the advise of every suggestion, my pockets would be empty and my truck damb near rebuilt. I think we all have alot to learn here. If you were wrong and your suggestion was wrong, then own up to it. Nobody is perfect, but at least we try, right. I take no offense, I appreciate everyones imput, except for those turds that decided to do a personal attack, instead of helping out. You turds know who you are. Rediculous and definitly speaks about your character and your intentions on this forum. Also, YLODISCO you should consider an appology. For you my friend are just a follower and you followed the wrong idiot.

 

You're right, I'm sorry..................that you are douchey enough to still hung up on this It's the internet take a chill pill son.

 

Whoa, what the hell is your problem, pal?

I've been here long enough to know that responses like this are unwarranted and unnecessary.

Grow up son, and get your head out of your ahs.

 

wow, heck of a post.

I will say that replacing the O2's will give you better mileage, I would only put 8MM plug wires on (I use +4 Bosch plugs too), and that O2 codes are not direct. I had a code for the drivers front O2 and it was the passenger cat that was cracked.

 

It is interesting to see that many technicians, especially the young, will follow the grail held out by the code reader. Old time diagnostics and detective work are fading into the past. It was good to see that the regulator solved the problem, but some thought had to go into that.

As far as all the finger pointing - that's hogwash. All of you know that you would stop on the road if you saw another Rover on the side with the hood up.... and that's what we are doing here, in the modern age of information technology, where ideas, both good and bad, travel at almost the speed of light. The guy typing a response might be ten time zones away, just finished working on his Rover, and came in to relax. Words of encouragement, some dry humor, and sage advice - all for the cost of a few watts to run the computer. Best damn deal in town, if you ask me.

And while I may not always agree with LRD2&ME, I have the utmost respect for someone that can dig up IED's for a living....

 

X2! Semper Fi

 

Full disclosure - my shade tree mentor was my father-in-law, 20 years in USAF SAC (Missiles), but WWII as Marine Paratrooper. Not so lean, not so mean, but still a Marine. Silver Star - Iwo. Wifey is 20+ year DOD employee at Ft Stewart. If you can't stand behind our troops, by all means stand in front of them...