well i was mainly looking for some better sound by removing that cat. but if its going to be dumping a bunch of unburned fuel then im just going to let it be.

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2003 limited 3.7L V6
Vader Edition

http://www.cardomain.com/ride/3219059

Doesn't it sound good with the upgraded muffler? People do a double take when they hear my exhaust and ask if it has a V8 in it.

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June 2001 Liberty Limited 4X4
Frankenlift II Premium, Al's Upper Arms, 245/75R16 C Silent Armors on Moabs, RL Skink Super Sliders, Rear DTT, Riddler Diff Cover, Fastman Throttle Body, Profinish-Proglass Hood, Borla Dual Outlet Exhaust, TransGo Reprogramming Kit, APS Stall Converter, 4.10 Gears, B&G Chrysler PCM, Lots of Line-X, etc...

Gotta love the feds! That's the fine for removing a federally mandated item.

I cant really see where removing the cats would make enough difference in our motors, now if you were going for every last bit of HP then maybe but for every day driving then no. Yes it would be louder sound wise but...trust me I have a garage full of old cats off of vehicles from several years back, that I took off and redesigned the exhaust system but the way everything is designed now not worth it.

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

I hung out with a lot of guys that had Ram/Dakota's with 5.2L/5.9L engines. One guy went to the track almost every week. Everytime he did a mod, he went to the 1/4 mile. On the 5.9L he did a cold air intake, then stainless cat-back. Each of those got him 0.1 and 0.05 in the quarter respectively. He then decided to straight pipe the cat... That got him .25 in the 1/4!!! And when looking back at all the mods, the only thing that gave him bigger returns, was a supercharger and engine build up. But for bolt-on type mods (or bolt off lol), the cat was the biggest restriction in the motor.

Now, I don't know how the 3.7L would respond to a cat-delete, but I doubt it would hurt! Unless someone has real world tests (before and after dyno, 1/4 miles, and MPG) it's hard to say what you could really gain (or lose).

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'03 Reny Cactus Green - All the comforts, Escape Hatch, Trac-lok, Selec-trac, Full disk brakes + 45RFE (built Sept 2002).
Had: '98 Dodge Ram 1500 SWB RWD 5.2L - I will miss you...

I was mainly talking about day in- day out driving. Yes going to the track is one thing. Stomp it and go wide open you need to get rid of a lot of exhaust gasses quick. But in real world driving how much good would it really do, thats what I was trying to get across. Two very different ways of going from point A to point B

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

Agreed. Most people will never notice it. But if you're looking for power gains, it is something that can be tapped, especially if you want power at higher RPMs. You most likely won't notice it in the power range most people drive in daily.

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'03 Reny Cactus Green - All the comforts, Escape Hatch, Trac-lok, Selec-trac, Full disk brakes + 45RFE (built Sept 2002).
Had: '98 Dodge Ram 1500 SWB RWD 5.2L - I will miss you...

So has anyone tried one of those O2 sensor simulators? I was hoping somebody could give me some feedback on those before I try anything. I was going to put the simulator on without removing the cat and see if I get any CEL and then do any work to the cat.

I also want to get the JBA headers when they come out. They haven't come out already right?? I think that will give alot more flow. Then I need to work on the intake, maybe throttle body.

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04 KJ Sport
K&N RF-1027
245/75/16 Kumho Road Venture KL-78 on Limited wheels

Down Right L.O.S.T. Florida #223221
http://www.cardomain.com/ride/2224536

Hmm, I'd do Intake/TB first. Reason being, this way you won't notice any low end loss (open exhaust, restricted intake = low end loss, though minor you may notice). Do the intake first, that will help with throttle response, then do the exhaust - you'll appreciate the exhaust more too since it'll work nicely together with the intake being already done.

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'03 Reny Cactus Green - All the comforts, Escape Hatch, Trac-lok, Selec-trac, Full disk brakes + 45RFE (built Sept 2002).
Had: '98 Dodge Ram 1500 SWB RWD 5.2L - I will miss you...

Considering you live in the US, you might want to consider federal laws and not just local emmissions testing. If you remove all 3 cats from your Libby, you could be looking at $7,500 in fines. Also, there are a lot better ways to get some more power to the ground. Here's what the EPA has to say about it.

http://www.epa.gov/otaq/cert/factshts/catcvrts.pdf

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June 2001 Liberty Limited 4X4
Frankenlift II Premium, Al's Upper Arms, 245/75R16 C Silent Armors on Moabs, RL Skink Super Sliders, Rear DTT, Riddler Diff Cover, Fastman Throttle Body, Profinish-Proglass Hood, Borla Dual Outlet Exhaust, TransGo Reprogramming Kit, APS Stall Converter, 4.10 Gears, B&G Chrysler PCM, Lots of Line-X, etc...

i'll put mine back on as soon as i find $950 for another new y-pipe because the old cats failed 2 times now. I'll huge a tree for you instead.

there are few performance gains to be made by removing them on a stock engine regardless of bolt-on's. (excluding forced incuction or NOS) the o2's in the rear need to be replaced by an o2 simulator www.o2simulator.com or somthing like it. If yours are cloging then you can spend the money or cut the pipe just after the cats use a BFH and a steel sewer pipe to "unclogg" them and weld the y-pipe back on. this will pass visiual inspection if you were to get pulled over in a DMV check point. oh yeah my gas mileage went from 11mpg to 16.5mpg so i think in my case i'm not hurting the spotted owl all that much.

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2006 Liberty Sport
OME HD springs
Rusty's strut spacer
Khumo MT KL71 245/75/16
K&N cone filter in stock box
1" polyethylene TB spacer
PEI aux-input
Mobil 1 everything
NGK front O2 sensors
rear O2 deleted (O2 simulator)
next up
- custom header-back exhaust (sans cats)
- EGR delete
sorry Mr. Gore

Yeap, the cat on my Truck was gummed up a little at 110,000 Miles. My highway mileage went from 16 to 20 immediately after straight piping the cat and putting on a straight through (rather than restricted) muffler. Wow!

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'03 Reny Cactus Green - All the comforts, Escape Hatch, Trac-lok, Selec-trac, Full disk brakes + 45RFE (built Sept 2002).
Had: '98 Dodge Ram 1500 SWB RWD 5.2L - I will miss you...

I have to say, coming from another platform its interesting to see this conversation. I have a 3000gt and it has a cali spec exhaust system. Basically there are 2 Mini cats, or pre cats that feed right after the headers.. they converge through the downpipe to the main cat, then out the back into resonators/muffers like the rest. One of the most common mods, is to actually remove the "precats" gut them out with a drill and put them back. This leaves the piping stock, but allows the restriction to be removed. Keep in mind, in the fed spec system there ARE NO precats, so gutting them just evens things out. A test pipe/race pipe/H pipe is one the cheapest and most effective exhaust mods one can do. Most of the restriction of airflow comes from the cat. converter.I am not in anyway condoning the removal of such, however, if it is there to improve emissions, and your emissions pass without it, nuff said. You WILL FEEL a difference going from cat to no cat and in most cases its a bolt on/off modification. In addition, IMO, if you have a 03 or newer car with Huge emission problems due to burnt oil, etc, you have more issues to deal with than a 5hp to 15hp increase. My humble opinion.