today i was comin back from deer hunting and it sounded like my truck started missfiring. going uphill about 55 mph it would make this occasional loud ping noise and it would shake up and down when i would turn the O/D on. ive been told it could be an intake leak or a messed up timing chain. i know its not the plugs or plug wires because i just changed those. also i put on a new cat converter and muffler because the cat was rattling if that may help. its got about 230,000 miles on it. thanks for any help.

 

Do a search here for plenum. Did you put a new o2 in also.

 

Did you put good quality plug wires on there? There is a TSB in the FAQ section for plug wire routing, due to induction crossfiring issues....... May wanna investigate that as well.

Given the mileage though, plenum is a very good bet.

 

Here is the TSB for the spark plug wire's. http://dodgeram.info/tsb/1998/18-48-98/18-48-98-v8.htm . But since the cat was no good, the blown plenum and the o2 sensor played a major roll in the CC failure.

 

they were good quality plug wires. i also forgot to mention that we put a new cap and rotor in at the same time as the wires. i did a search on plenum but im still not sure what that is.

 

Take the intake manifold off, the plenum is a pan bolted to the bottom that keeps the oil out of the maifold