So, I think I've actually figured out my problem, but I figured I'd make a post here so I wouldn't be THAT guy, who reads and reads and never contributes.

I bought this truck about a month ago with 120K on it, from a very old man, don't even think it ever hit full throttle till I drove it!

Anyway, it sat for some time, and always started right up, and seemed to run great. I had to replace some brake lines, and shackle mounts, but that's just due to the age, and everything seemed to be going okay, but the truck had some wierd hesitations. I thought it might have been spark/fuel, so I put in an air filter, some new plugs, and changed the fuel filter while I was at it. I also moved the 7 and 8 wire away from each other. This seemed to help a bunch, until yesterday that is.

Put about 200 miles on her yesterday, which is the longest I'd driven it yet. By the time I got home, it had almost no power, was bogging very bad, and tended to lose speed. I was perplexed! So, I brought her into the garage, and even though I'd never seen a check engine light, pulled the codes. NOT ONE STORED!

This got me even more confused, so I checked fuel pressure, and I had plenty of it. I checked for vacuum leaks with propane and a gauge. Not one leak. Oil and coolant are clear, it doesn't overheat, had great oil pressure. Pulled out the MAF, cleaned that up well, it did have a little residue on it. Checked base timing, perfect.

Took it for a spin down the road, and it seemed better, for the first couple of miles, then it was just as bad. Pulled her back into the garage, and racked my brain.

Then it finally hit me! The catalytic converters! Checked em with a digital temp gauge, and after only running the thing for like 10 minutes, it was up to 450 degrees!

So, I pulled out the O2 sensor, and drove her home. Throttle response and low end power is back for the most part, although she's starving for exhaust into the higher RPM's.

So the only question I have now, is this. Anyone know what the going rate is for both of the cat's on one of these things? What they classify each as?

I'm tempted to pick up the walker or magnaflow Y-pipe, but a little short on cash this week. If I can get 140$ or more for the cat's, then I'll be alright, but if the value is little to nothing, I might just weld up some tubing in the cat. I'm not trying to make this a performance machine, just want it to run a little better, get better MPG's etc. Also, if I do this, are their any problems with removing the smog pump and which belt do I need to do this?

Thanks for reading!

Chris

 

Cheap fix, cut the pipe and gut the cats(ram a pipe inside to break it up). This will get you around til you can get new ones.

 

Still haven't had a chance to gut the Cat's, although I'm beginning to wonder if that is indeed the problem. I blocked off the EGR, and checked the codes again. The only code I picked up was a CM 172. I'm pretty sure thats just from when I ran it without an o2 sensor for a few miles. Nothing on KOEO or KOER. 111's all around.

Fuel mileage has gotten progressively worse, somewhere around 5-6 now? Seems to start up fine, has a lot of stuff that comes out of the exhaust (Espcially after seafoam) and I have yet to have any wierd smells (besides gas) or see the Cat Glowing. Any other ideas? Anything I can eliminate quickly before I'm able to gut the cats?

Thanks guys!

 

what was the fuel pressure at? you checked the timing with spout connector removed and it was at what? when your pulling codes your doing both the KOEO and KOER? you put the egr back together right and the o2 sensor is back in the exhaust correct. did you install larger tires since you bought it?

 

^^^ Try this

 

53 PSi Off, 39ish idling, couldn't test with a load. Timing is at 12deg, EGR is back together with a block off, but everything is left hooked up and installed.

Yes, as I said above, I did both tests. The O2 sensor is installed again. I'm still running the 235's for now.

I guess I'll just have to cut the pipe and clear the cats. Just trying to get the correct combo of a garage with heat, a welder, and ample space for this pig. Not too mention some free time! I'll keep this posted.

 

So tonight, I gutted the cat's. Rear was pretty solid, almost completely intact. Front one I couldn't see, but I used a long somewhat flexible bar, and it punched through pretty easily. It's definately a little bit better, but still doesn't seem 100% Seems like the truck is either all or nothing. If I floor it, it downshifts and has power, but at part throttle, it seems like it takes the rev's forever to come up.

On another note, on my way home, I stopped for literally 2 minutes at a store. The temp gauge was around the N-O. When I came back out and pulled on to the road, it was down below the normal range, and within a mile down the road came back up. I've never noticed this before, is this normal?

Gas mileage seems to have corrected itself some.