tylerspyler

Ok, so i have a unique question. I have a 2001 xj and i would like o make it a little quieter at highway speed. it is all stock and I do not plan to use it as an offroad vehicle.

I just want to know if putting a resonating muffler in the exhaust sytem will help with noise? It has the Cali, emissions with 3 caltalic converters. "IF" I did replace the final cat with like a small muffler or resonator, would it help (no o2 sensors after cat, and no testing). Of course this is just a theory, but would it work?

XJdryva

The mechanical fan under the hood is 2x as loud as the stock exhaust. It would be a waste of time

HiPoint

The mechanical fan shouldn't be roaring at highway speed.

To the OP: I would leave the cat alone and maybe put a small resonator muffler in between the muffler and the end of the tailpipe. This is the setup on a LR Discovery and they are very quiet at highway speed.

tylerspyler

Not at highway speed, the viscous fan is usally running the same speed as the air going by it once it has reached its dissengagement temperature. Not that your wrong but, the exhaust is a smidge louder at speed (70-80mph) than all the other noises on or in the jeep. It is quiet at idle but i do not plan on idleing it on the highway. plus the hills cause the egine to stay in 3rd gear at 3k rpm, its not what you would call quiet.

tylerspyler

To the OP: I would leave the cat alone and maybe put a small resonator muffler in between the muffler and the end of the tailpipe. This is the setup on a LR Discovery and they are very quiet at highway speed.[/QUOTE]

That is true, but there is not alot of room there to be putting one in. The reason I said to replace the cat for the muffler, is becausei belive the cat is mostly plugged from the original owner letting it sit for a year and then running it with the stale gas. Oh well, I guess its time for a little trial and error.

XJdryva

That was an example of how 50 other things on cherokees are louder than the stock exhaust. Wind noise will never go away and just the engine itself doing it's thing is noisy. It's a hopeless cause. Just dynomat the floor, ceiling and doors. Then you'll only have wind noise to deal with. Drive in on the moon if you want to get rid of that

freegdr

you want quiet have a old gm muffler installed from the 70s era

tylerspyler

Thats my point. I have taken care of the wind noise, the rattles, the squeeks, the tire noise/road noise, and engine compartment noise. thqat leaves only the exhaust. I plan on putting a socond layer of dynomat in after the weather warms up.

tylerspyler

I would if it would fit, and be in good shape. I was looking at using the rear resonator off of a 04 dodge dakota v8, they are small and are inline like I would need, but finding one will be a challenge or will be pricey.

XJdryva

Wow I'm impressed. I can't believe with all that emmissions crap under there that it could possibly be any quieter. I never heard my stock exhaust over the walbro fuel pump

tylerspyler

I'm pickey i guess. and yes it is quiet at IDLE, but at 2k or 3rpm, it hums louder than I like.

keep in mind my 2000 xj was running a glasspack and a 3.5 inch tailpipe. and i had a bad case of leadfoot syndrom.

djb383

A glasspack vs stock muff?......really? Isn't a glasspack like 1db shy of a straight pipe? LOL

XJdryva

My glasspack is pretty quiet. I can't hear it over the wind noise on the highway