Yes, even if you don't have one because you or someone else took it off, a catalytic converter is required. JF policy is to close any thread that discusses removal of the cat.
00 4.7 Laredo...KYB gas shocks, ADDCO rear sway bar and Firestone Destination tires.
08 Z71 Suburban, front leveling kit with rear spacers. 285/65 18s Nitto TerraGrappler G2s
94 5.9 Laredo 6.5 RE lift with 35 Maxxis Bighorns
and 33 Bridgestone Duelers
Detroit and true trac
Red Jeep Club Member
Texas Jeep Owner #6
USN Jeep Club #4 http://www.kevinsoffroad.com/
That is very communist of the forum, but I see how it is a good idea on the forums part
bottom line with catalytic converts are, that you will not net any gains from removing it. The back pressure a high flow cat offers gains you power vs a straight pipe in any situation. That coupled with the loss of mpg, because your trucks check engine line will come on, and the ecu will run in open loop safe mode all the time, its stupid to do such a thing.
I like the 18" pipe muffler I have. I have a 318 though, I dont know if I would recommend this on a 4.0, it may get a bit tiney and ricey of a sound going on.
my video, don't mind the brake noise, they where wet and I was being cautious. Thats an 18" pipe where the muffler once was, everything else stock. No power gains that I know of, just noise, but oh so good noise.
I just picked up the magnaflow glasspack. Decided to go with it because from videos I watched they sound good and it was only thirty bucks and pep boys. I also don't really care what my neighbors think. Especially because they already put up with this jack*** that lives across the street and he doesn't even have a muffler.
Just got the glasspack on. The only thing I had to buy was three clamps and an adapter. So the whole thing only cost me about $40 and it sounds awesome. Nice low tone that isn't annoyingly loud at idle and it's really loud and powerful sounding when I rev it. I've already noticed an increase in power. Now I'm thinking about adding a cold air intake.
With the stock stuff in front of the glasspack you should be alright for a long while. It has always amazed me at how far back mopar will push that converter. I was under the impression for them to be effective, they need to be at a certain point in the exhaust stream, like way closer to the exhaust manifolds.
I am also confused as to why my truck, whos honeycomb is bouncing around in the stock cat, has not thrown a downstream o2 sensor code for cat effeciency. Odd.
Yeah I want something that gives my 4.0 like a deep aggressive sound but not overkill, not like a Honda civic with 3 foot tall spoiler kind of sound. What would I need to achieve that sound I want? And where could I get it?
your motor is to big and to different to a small displacement honda motor to ever sound like that. The worst you could do with a 4.0 is just be annoying and not very good sounding, thats all. Get on you tube and start listening. The proof is in the HD video pudding.
I just put on a cold air intake minus the cold air part and it made it sound much louder on the back and under the hood. When it gets up around 3000 rpm it starts to sound like a muscle car taking off. I love the sound it gives a 4.slow. But it'll probably kill my MPG, but it is a Jeep.
I'll post a video of it soon and I'll see if I can also make it so you can hear the sound on the front end.