I have a 1999 Dodge Ram with the V8 and it starts right up but once I get going it wont go over 20 mph then dies and is hard to start agine. Any info on how to fix this would help. Thank you.

 

This sounds a lot like a clogged catalytic converter. Unscrew the upstream oxygen sensor to relieve exhaust pressure and take it for a spin. If the symptom is greatly improved, you've got a clogged cat, and almost certainly a blown intake manifold plenum gasket to go with it. There is also a strong possibility of a cracked head, as the overheating of the combustion chambers that accompanies a clogged cat quite often causes the heads to crack.

Also, if it's a clogged cat, you'll want to replace that upstream oxygen sensor along with the cat. The same oil that clogged the cat will foul that sensor.

 

+1 on everything that Unreg said

 

Yup same thing happened to me on the highway towing a 6x12 trailer packed full....i just cut my exhaust and used a 4 foot piece of threaded rod to hollow it...cost less than $10 to fix the problem

 

You can take out the pre-cat O2 sensor (physically remove it from the pipe) and see if it runs any better, if so, gut that puppy or take it out, depending on the local laws in your area. Feds says you have to have a cat but I doubt they're gonna check, local emission laws are usually more enforced...

 

Looks like someone else needs to read the plenum stickie. Gutting the cat is not going to solve the problem. UnregisteredUser is spot on.

 

No, it's not going to SOLVE the problem, but it may help the poor lad get past 20mph.......

 

Definitely clogged cat same thing happened to me but I just happened to have one of those fancy exhaust cutters that's a chain hooked up I don't know how to explain it but its a lot easier than a sawzall or grinder might wanna invest in one its really convienient


Here's a video of it in action

https://www.google.com/url?sa=t&sour...KmmCVs3nnq3cCg

 

Thanks for all the help. Looks like I have some work to do this weekend.

 

Sorry, did not intend to upset you.