i have a 97 3/4 ton with a 5.9l gas. on the way home from school one day it fell on its face and wouldnt go over 10 mph. i got it to a parking lot and scanned it. all i got for codes were random misfires. after playing around with it for a few hours it started up and ran ok. halfway home it fell again this time so weak i had to put it in low range to get it home. and there were no codes. i changed every sensor. cap coil rotor wires plugs. fuel pump, iac intake manifold gaskets. did a compression test on all cylinders (125-135lbs). fuel preasure was at 55 lbs. a timing light showed no. 1 firing within designated area. also set no. 1 at tdc and checked rotor orientation it was fine. please help im stumped. never had a dodge i couldnt fix. i figured a fellow mopar nut may have an idea i over looked thank you.

 

i also tried switching the pcm with my 97 offroader also with a 5.9

 

That sounds a lot like a clogged cat. Unscrewing the pre-cat oxygen sensor so the exhaust has somewhere to go will tell the tale if it's so. If it clears up, do something about that cat and keep on truckin'.

 

hey i wanna say thanks alot! i took the first o2 sensor out and sure enough it started. i knew i there was something i wasnt thinking about. the truck is running great and back to work.

 

Gut that cat outta there! I straight piped were the cat used to be on my 97 ram 2500 360ci. What a difference it made! Plus were are weight exempt from emissions!

 

You're welcome!

Please tell me that you either gutted or replaced the cat and now have the oxygen sensor back in place. But if you don't, do that right away. If you don't, you can look forward to burnt exhaust valves and cracked heads, with the first to go being the even bank, cylinder eight.

 

Ehhhhh, I wouldn't gut the cat on a gas truck. While we are weight exempt, the engine needs the back pressure from the cat. Down the road you'll be asking for problems.

 

i have had problem with 2 cats, and really want to cut it out if you just gut it are you going to be ok? i have already gotten mouth fulls on the back pressure i just want to know if the engine will run without messing with the air/fuel ratio?

truck is a 96 5.9L

 

Im running no cat and havent had any problems truck runs great and many others will say the same.
1. you can either cut it out and replace with a piece of straight pipe
2. if you dont have a muffler bang on it with a big hammer and blow out the crap
3. take the cat out and take a small pipe and knock the stuff out then put it back on so it looks like you still have a cat

 

these options throw the CE light on or no?