aim4squirrels...was meaning absolutly no disrespect with my previous post. That O2 sensor threw me off for a damn year. I would pop a CEL for the rear sensor which I knew wasn't the problem so I changed everything else out.(plugs, etc) Truck ran like pure crap about 30 sec after starting and woul come out of it after a min or two but was getting progressivly worse and began hesitating when giving it gas after stopping.
Finally said the hell with it after dumping $300 or so on everything else and change the rear sensor. No change BUT ...CEL for front sensor come up and that was it.

 

Ok, so when it starts doing this the truck acts like it's going bananas? Like a WOT situation ect ect? I had an intermediate TPS problem before on my 01 that caused my truck to hickup every now and then. Took me forever to track it down because it never threw a code for it.

 

really, I'm not upset at all.

There's guys around here that are really hung up on always being right. I'm not one of them. I'm absolutely fine with being wrong and owning up to it. That's how we all learn.

Heck, Last year I posted up about a real hack job I did on a brake cylinder upgrade for a 2001, because I didn't want anybody to have to go through that. If somebody else tries it and posts up some success, I'll be most impressed and fine with being wrong.

 

You could still be right. I havent been able to work on the truck since the last time i posted.

 

Well I had the same problem, but it was that the computer would open the egr valve. When I pulled off the egr vaccume hose, It never did it again. Dont know why it happens all of the sudden, because it didnt do it before. maybe the plenum leak has to do with when the egr opens.

 

I found a problem with the O2 sensor, dont know if its THE problem but it is A problem. I post pictures of it tonight.

 

Well problem is solved. It was the front O2 sensor. The one at the very beginning of the CAT.

a few years back my father had the cat replaced by a shop, supposedly he knew the guy. Well after they replaced the cat when they reinstalled the O2 sensor they cross threaded it and just kept wrenching until it wouldn't turn anymore. It was still a quarter of an inch from flush. I had one hell of a time getting it out. Retapped the threads and installed a new O2 sensor. Drove it to work on monday and hauled a couple of cars that same day. No problems at all.

Thanks to everyone who helped!

 

 

Doing a search for problems like the ones i'm having i came across this thread and its very similar to what i'm having. So what i get is that i's ok to disconnect the o2 sensor and drive it to see if the truck acts up still? If so is there a certain distance i shouldnt go over driving like this? The trucks a 98 1500 4x4 with about 68,000 miles. I realize its probably getting close to the time when i'll have to replace the sensor anyways, but i'd hate to have to do it now if its not the problem. Because of the hesitating also made me think of the fuel pump. But i'd like to test the O2 sensor before moving on to testing the fuel pump, ect...

sorry for posting this in a long dead thread, but i figured it'd be better than starting a new one for the same problems.

 

I believe the truck will still act up without the sensor. That sensor monitors the exhaust to set the fuel ratio for the motor. If it's acting up because it's bad, I think it would probably do about the same thing disconnected or removed.