Ill start at the beging, the other day my muffler fell off due to the horrible job done by the previous owner and the cat was about to fall off to, so i replaced it with a stock cat and i got a cheep glass pack to try it out. after i get everything put togethere and drive down the road when i hit between 40-55 my truck feels like something is slipping it shakes and feels like your lightly taping on the brakes. so i took the glass pack off because it was running fun with just the cat and pipe and it is still doing it. i just had my rear main seal and oil pain gastket replaced, now i need my vavle cover gasket and u joints and ball joins and wheel bearings done. im trying to do as much as the repairs my self so any input will help!

thanks
patrick
o and it has 97k on it

 

Given your symptoms, I don't think its a trans issue, what I think you are seeing there is an engine miss. At right about 45mph, TCC locks, and the trans goes into O/D. if you have a miss, that is when it will be most apparent. To check and see if that is actually the case, go out and drive the truck at 45mph, when it starts shaking, hit the O/D off button. My bet is, the shaking will be dramatically reduced.

 

i tried that the other day and it doesnt shake as much as long as im not going up a hill but when i got up a hill it like o/d is on so you thing i need to replace it?

 

Pull your #8 plug and see what it looks like or take it to any parts store and have then check for code's, just because the check engine list isn't on doesn't mean there isn't something in there.

I had a blown plenum and the #8 plug fouled out, truck shook like crazy at 45, actually I couldn't get any faster then 45.

Have you fixed your plenum yet?

 

i havnt tried the plenum gasket because im still relatively new to the whole DIY, but new plugs and wires will hopefully be bought next week. but is their an online manuel to show how to replace the gasket or just a good online manuel. i just bought a haynes and didnt see anything about the gasket in their but i just looked real quick. also when im at a stop light it shakes but when o/d is off it shakes alot less and smoother ride all around.

 

There is a manual you can download in the FAQ/DIY section. ALso, read the Be ALL End ALl Plenum sticky thread at the top of the forum page.

 

98 Ram = blown plenum gasket, bad o2 sensors and the Pcv,cap,rotor and wires,(and if it was ever replaced, o2 sensor also) bought from Autozone most likely. That equals junk, and time to do it all right.

 

You have a misfire.... before jumping to any conclusions give it a tuneup... judging by the work the previous owner did on the exhaust you need a tuneup and it may very well fix your misfire issues... I had misfire issues it took months to track down...
Replace your plugs, wires cap and rotor.... any one of these is a common cause of a misfire.... and a hell of a lot more practical than assuming its something bigger ripping the intake off first...

even heavy carbon buildup can cause it.... seafoam might help... my misfire started when my transmission shop cracked one of my headers giving me an exhaust leak while rebuilding the tranny. Ironically just replacing the headers alone did not fix it... I would look at possilby replacing your 02 sensors...at least the precat one... since now you replaced the cat and the exhaust flow it sees has changed dramatically.

 

well i replaced one of the sensors because it was welded to the cat ( that is the one farthest from the engine) and left the first sensor alone now should i replace it? and hopefully today i can get to napa and get plugs any recomendations?


so i got in my truck this morning and my check engine light came on so i hooked up my code reader and p0304 came up so it looks like a miss fire?

 

You should replace the pre-cat O2 Sesnor.

I use plain AutoLite Copper Plugs in my truck. Seem's our engine's don't care for the fancy plugs too much.

I'd bet my bottom dollar #8 is fouled up. When I pulled mine I cleaned it up a bit, which helped for a few minute's then it started to miss again. Found a crack in the plug when I put a new one in.