Hello all. I have a 2001 Ram with a 318 in it and it will run fine when cold but once it warms up to about 210 degrees it backfires and sputters like no other, won't hardly idle, and if it shuts off then it won't start until it cools down. I have replaced the crank sensor, cam sensor, ignition coil, spark plugs, and rotor button to little success. Now that I have replaced all, with the crank sensor being the last thing I replaced, it will idle once it warms up, but if I rev it up it misses and crackles like a popcorn machine exploded haha. I'm at the end of my wits about it so any help would be appreciated. Thanks in advance.

 

Welcome to the forum.

What brand cam and crank sensors? These trucks don't like aftermarket sensors very well. Not sure if the plenum could cause these issues, but is your pleanum Bad? Look down the throttle body or take it off and see if there's oil pooling in the bottom of the intake.

 

Crank sensor is rock auto and cam sensor is from federated auto parts. I looked in the plenum and it looks to be pretty clear. Is there any chance if the catalytic converter is broke up inside or melted that it would only cause troubles once it gets warm because it honestly sounds like it's just got pieces of catalyst inside of it blocking the exhaust

 

I would check for a clogged cat if that is the trouble. The power loss your talking about once it's warmed up show some signs of being clogged, or at least is a typical sign. If the truck was burning oil from the plenum before, if it's even been fixed it will clog it right up.

Grab one of the laser temperature testers, and check the temperatures before the cat, and after the cat. Output hotter than input = a good cat... anything else and it's bad.

Try that and get back on your results.

 

Thanks I'll surely try that! And one last question, I know that gutting the cat or just cutting it off on most vehicles doesn't really hurt power and performance, but I heard that when you do away with the converters on these 318's that they lose all kinds of powers. Do you have any idea how they do?

 

I'm not sure about all the losing power if it's true or not. I don't have crazy experience, but I still try to help out.

I would ether buy a stock cat, which flow actually pretty well, or go with hi-flow cats for it, and why not just put an exhaust on it while your in there ya know .

But gutting is also an option. It might throw a code on the downstream o2 if you gut it, but who knows.

If the cat is clogged, I would do some looking and pay close attention to the plenum. If the cat clogged, then it either has a lot of miles, or burns too much oil, wether that oil is from a specific source, or just because the engine is worn out.

 

Well it needs exhaust any how and I'm definetly going with 2.5 inch straight pipes but I just wasn't sure wether to keep the cat or not lol. The truck only has right at 200,000 miles on it and I bought it from the daughter of the original owner and everyone says he always took care of the motor so I'm just not sure how ragged out it could be.

 

I think the first thing I would try is simply unplugging the front O2 sensor, and see if the truck runs any better. If it doesn't, physically remove the O2 sensor from the exhaust, and try again. See what happens.