If the honeycomb broke loose and clogged the exhaust - it usually will not rev up to the rev limiter and you will hear a massive sucking sound, like a 4 barrel carb under a heavy load, but you will feel very little exhaust pressure coming outta the tailpipe..

The clogged cat issue is very very common on these trucks... And the symptoms and the cause (sharp bump) are very likely for a clogged cat..

 

Yeah it has something to do with the rebound rate of the spings and shocks.

And a LMTV airborne?? He probably had a sore body for the next couple days, those things ride rough.

 

Also i got to thinking, depending on if you're running stock manifolds, the bolts that connect the Y pipe to the manifolds on the drivers side and passengerside tend to either rust appart or the retaining clips pop out of the bolts and it will cause the Y pipe to drop down enough to break the seal between the Y pipe and manifold. Mine did this once and it took for freaking ever to figure out what the hissing sound was and it kept getting louder and louder with every hard bump i hit.

I pulled it up on the ramps and realized that the Y pipe had been shook loose from the manifold, i went to home depot and bought some stainless bolts and just replaced them and to this day i havent had an issue with it.

 

Thanks for all the replies! Answers to some of the questions so far:

@Yakkier, KYHI and Daily Driver - I tried pulling off the precat o2 but no change. If the honeycomb did break loose, I'm guessing a muffler shop is in my future?
@Foxracing584 & Sheriff420 - I did a basic inspection and I don't see anything loose or hanging. I'll look again in the morning.
@Gevalco207 - It appears to exhibit the same behavior when I run and rev the motor when not in gear.

Also, I took it out around the block again tonight and when I got back to test it running while not in gear, I had the engine light come on. I pulled the code and got P0301. I looked it up and found the following:

http://www.obd-codes.com/p0301

I'll check the plug and wire tomorrow. Seems to jive with what I'm seeing.

 

i like the look of your truck! is it 4wd or 2?

 

^ I agree, that's a nice looking truck

 

check if the spark plug wire on #1 fell off or got burned up.

 

I'd gut the freaking thing or take it off completely, weld in a slot/nut for the O2 to screw into and be done with it.

 

P0301 so did sum thing happen to you number spark pug wire?

man 6 Banger so a lifted 2wd? get sum pics up

 

i was bored and googled P301....... this came up......

http://www.pirate4x4.com/forum/showthread.php?t=337312

maybe some ideas for ya?