Hi everyone. Will removing the cat converter alter the sound of the exhaust? Also, is there a way to bypass the sensor so that the warning light wont come on?

 

Yes, it will alter the sound of the exhaust.

 

what sensor? Are you talking about removing all 4 cats? As far as I know you can take the second set off with no problem, but the ones with the o2 sensors will definately trigger the check engine light. It would not be a good idea to bypass them, as they adjust the air/fuel ratio, but Im pretty sure you can (although it would be more trouble than its worth) if you get some kind of "piggy back" FMU.

 

you need to plug in the O2 sims, if going catless.

 

But why do it at all?

 

Won't you fail the emissions test without it?

 

I wouldn't do it. The xfire already has a nice sound with the stock exhaust. I think cutting the cats off will give it a cheaper sound, and I doubt you notice anything as far as HP gains / back pressure differences go. Not worth it. Buy you a full after-market exhaust system if you're going for more power and maybe a different sound.

 

Hit the Department of Transportation web page or web page of the state currently residing in for answers on Cat converters and the penalties for removing them. There is "0" performance gain by removing a functional converter. Put playing cards and clothes pins on the spokes for a cooler sound...

As Xfireblur says...The Borla system on the NA xfire is perfect.

 

no cat= more hp.

all you nee to do is install quick release clamps on the straight pipes, drop them out and clamp on your cats for emmisions test. this also will save your cats in the long run, won't need to buy them when they fail if you don't use them. I've been doing this for years on all my vehicles. some vehicles will gain 2 mpg with this mod.

 

Not in a gayfire, removal will only make negligible numbers on a street car. There many other things to do to a NA or SRT 6 that are worth more and legal. The 70's are over, super restrictive cats are not the issue they once were. The automakers are being strangled by CAFE mileage requirements, and actually have insentive to make hi flow cats. Random Technolgies is one manufacture making after-market cats that support 1000hp cars.

 

BS..oem are still restrictive, and aftermarket cats will set off your warning light beacuse they do flow better, but not that efficient at cleaning the unburned gases.

I have monolythic cats on my Silverado, took them off and gained 2 mpg. so you can't tell me the monolythics are non-restrictive. this is worth the cost of materials, if you added up your fuel bill before and after for the year especially at $3.80-$4.00 per gallon, 2MPG adds up, so it's all gain, even if you make 5 extra hp.

 

I wouldn't advocate information like this to one of the forum members, that doesn't present the implications of getting caught without one and the actual no BS performance results. Again, benefits would be minimal, espeically on the NA car. Your self fulfilling prophesy of superior gas mileage isn't an objective emphirical test and doesn't mean much to me, sorry. Not with-standing an increase in gas mileage, still doesn't reveal that these were properly functioning CATs when removed. In the mid 70's and 80's dumping the CAT's did work for performance, and the inspection for these wasn't strict. Many states, now look for cut outs, not just the presence of the CAT. Look up the penaltys before you advocate to young guys that they need to chop them out for a net gain of NIL. The states are only going to become MORE restrictive about emmisions checking, not less.

The after market CATs made by Random Technology are the way that professional shops go, especially with sensitive OBD2 cars. They are large and free flowing and don't cost much money. That's my advice to give if guys must do something with their CATs, but when you are talking about a 220 hp car, the minimal results don't outway the negative aspects of removing them.

 

I gutted the cats on my Charger and it gave me a little more power/torque and a unique "dragster" like lope at idle. The downside is the CEL that's always on and the SMELL that will fill your garage and your clothes and your nose at stoplights. After 8 months of being catless I am putting some OEM cats back on the car this weekend just to rid myself of the smell(my girlfriend always mentions) and the check engine light on the dash.


Just in case you guys don't know, the EPA is cracking down on the people that make/distribute O2 simulators. They are receiving heavy fines and are being forced to recall the sold sims.

 

by removing the two rear cats you will still pass emissions, yes it will alter the sound alot, and in my opinion is stupid on this car. Some cars yes and some no, my srt-4 yes huge amount of difference in performance and sound but that is turbo, on this car you will not notice a difference and the sound will be horribly cheap sounding. i thought about it but installed my exhaust and wouldn't want it any louder or any different sounding i know how raspy it would be without cats, if removing all cats the light will come on and you would need to do something with the o2's. I am planning to add high flow cats in the two rear ones if anything with my exhaust, but not even sure if i will bother with them. Id say the stock cats will flow fine for what the crossfires got. Its not always based on getting the least amount of restriction possible, some cases you can lose power, depends on the car.

 

Hey guys thanks so much for the info. In SA where I stay a cat is not a requirement. I'm not trying to gain more HP (although it would be nice). I'm just trying to get a better sound from the 3.2 V6 that's a bit too quiet for my taste.

Any suggestions? I dont want to fit an entire new sytem, just want a bit more grunt from the motor...

 

magnaflow cat back cheap and you can install it yourself in an hour, i paid 425.00 for mine shipped and it sounds amazing. look it up on youtube under username tylerxfire. Thats the only way your gonna get a real nice sound and not just noise. or just change the muffler if you wanna go the cheaper route to a different more aggressive one, the magnaflow is also sold in just a muffler and not a cat back. Imo go with the cat back you will be happy and its a good price. chuck466 is the user on here i went through for the best deal. Its just from rear cats back and all you would need, great sound little more power

 

Cut off the resonator and alter the mufflers after that if you still aren't satisfied... leave the cats alone.

Cheers!

 

Thanx MMZ, I think i'll leave the cats on for now. The guys on the SRT section said that only the SRT's have resonators. Is that right?

Also, what do you mean by "alter the mufflers"? Sorry about all the q's, I just dont want to mess up my baby!

 

there is no resonator on the n/a crossfire only the srt-6, you could just buy a aftermarket muffler it would change the sound, no power gain really just sound different. more aggressive, it would just replace your muffler not the whole pipe to your cats.

 

#1 the magnaflow system does not replace the exhaust all the way to the rear cats, it only replaces it to the y pipe.
#2 removing cats reduces backpreasure and torgue in most small displacemeant na cars, removing the 2 rear ones might net you enough hp to make the torque loss negligable.
#3 the exhaust systems that are from borla and magnaflow currently, both are great manufacturers and very reputable, niether system requires any cutting and both are bolt on
#4 a muffler replacemeant may net you some gains in power, but nothing noticeable
#5 only the srt has the resonator stock, but the borla system comes with a resonator regardless of weather or not your car came with one
#6 changing the exhaust on these cars even with the cat back system does not give a huge increase on its own
#7 i personally run the magnaflow system, its fulkly polished stainless steel, with no resonators, sounds great but not too loud, it is a bit of a b**** to install but well worth it! there is a thread on here about installing the system, check it out! there are also alot of different exhaust clips for our cars you tube, try looking around on there to find the sound your looking for. most of those people are also members here! hope you find what you need!