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Removing The Catalytic Converter In My Car

Is there any harm removing my catalytic converter?

Removing converters is a fool's game.

The illegality of it has been mostly a technicality, but I expect that to suddenly change very soon. The EPA, like all agencies at all levels, is hurting for budget dollars and they know how to improve theirs: more fines. They have to know (partly from forums like this) that there are lots of cars without required catalytic converters on the road, and every one of them can get the agency at least ten thousand dollars. I expect to see enforcement checkpoints soon to catch violators, probably using roadside "smog dog" equipment to identify cars putting out the tell-tale cloud of emissions. They would be pretty stupid not to. They don't need to prove you removed the converter to levy the fine - you would have to go to court to protest it and would you really commit perjury (a felony)?

Removing Catalytic Converters. Why?

if you were to get headers and like a catback system or something, you would want it off. it's basically a muffler. it does not increase horsepower by taking it off, it very slightly decreases it because you're loosing backpressure. taking it off is definitely a good idea if you have any kind of performance exhaust situation, not in any other situation....there are going to be people that this question pisses off and they're going to tell you it's a bad idea because "i want me kids kids to have oxygen in the ozone layer when they're born"....f#$% that! take it off if you do anything to your exhaust. i had a ford escort zx-2 back in the day (hardly a speedracer) but i got headers and exhaust put on professionally....it made it quite faster because i had an expensive flowmasters muffler and gave it a little more of a rumblin sound but i was not happy, i wanted some quality noise. i took it to a shop and they set me up with a removeable catconvert so for inspections (every 2 years here), i'd be able to have someone put it back on but man, when it was off, i loooved my car. it sounded good....oh...i eventually had to take that muffler off that (mufflers do exactly what their name is, they muffle sound) so i just had it straight piped all the way back from the headers and my god, it was loud and sounded high quality from pretty far away and close.

Can I remove my catalytic converter?

Technically it is illegal. It is federal law that requires a catalytic converter. However, if you do not live in an area that inspects cars for emissions, it is highly unlikely that anyone will find out.

Removing the cat decreases back pressure. This leads to a more efficient burn, more power and better fuel economy. However, you might need to adjust some of the sensors and computers to deal with the change. But, if you are modifying you car, new sensors are probably already on the list.

Also, you might want to be careful where you take you care for service. If you don't do it yourself, you will want to make sure the mechanic you visit doesn't care. Even if you do not have emissions checks in your area, some mechanics refuse to work on cars that have the cats removed because they could get in professional trouble.

Will removing a Catalytic converter from my car make it louder?

Yes it will. It might not be super loud with the stock oem muffler but if you were to put on a after market muffler then the exhaust will be louder. As for performance, you will not see much of an improvement on a bone stock engine. Actually in todays newer computer controlled cars you could decrease the performance/gas milage by removing the cat. The computer systems are actually tuned for the cat to be in place. Even on mild modded cars there is little increase in performance with removing the cat.

Does removing your catalytic converter make your car faster? or is it bad?

It all depends upon what you have done to your car to determine if removing the cats will make it faster or not. Removing the catalytic converter on a stock car will probably get you 5 h.p. or less, but if it has been modified you will probably see more. If you have a turbo on your car or other form of forced induction, the back pressure caused by the converter would kill a substantial amount of power, say 10-15 h.p. if not more. Places do sell high-flow cats which flow almost as well as straight pipes and keep you emmissions legal which would be a plus depending on where you live. I know when I removed the emmisions equipment from my dads 88' f-150 (smog pump, catalytic converter) it gained 2 mpg but I didn't notice any power gains (it's stock). Now lastly removing the converters can be either easy or somewhat difficult depending on if you have an after-cat o2 sensor. If you don't have one, swap in your pipe and go. If you do, you will have to purchase a programmer to deactivate the sensor or buy a o2 cheater
which cheats the computer into thinking that you still have the cats. Removing the converter without doing something about the after-cat o2 will send off a "service engine" warning because the computer either thinks the converter is broken, or somthing is wrong with the sensor. Either way you might loose some power. One other thing is that exhaust systems w/out cats, in my opinion, sound a WHOLE lot better. Converters give a gassy, raspy noise to cars that make them sound like they just ate some beans or somthing. But if you like the constipated sound I guess thats cool. Sorry for the long winded response, but I had alot of free time. Hope this helps.

Can removing the catalytic converter cause damage to a vehicle's engine?

I really don't know if running without a converter would cause engine damage but it is at the very least illegal in the us to run without one on a car that came equipped with one from the factory.

It would cause some unusual readings in the car's computer without it as the oxygen sensors (if still in place) would not have any differences to measure.

In either case, not a good idea and if you have local emissions testing, you will fail.

If I remove the catalytic converter on my car will it make my exhaust system sound good? The midpipe is stock.?

if you remove the catalytic converter from your car, you will need to replace it with a straight pipe. if you do this correctly, with a pipe that fits exactly, it will change the sound to a more deep throaty tone. however, you say that she purchased an exhaust system. does this mean catback exhaust, or a full headerback exhaust? if it is the full exhaust, from the engine all the way to the muffler then deleting the cat will change the sound dramatically, giving you that tuner sound. if not, it will sound more of what people call a "rice" sound. [meaning it will be loud and not good] i would suggest getting headers, deleting the catalytic and replacing with a straight pipe, and using an aftermarket muffler. [i use a flowtech raptor, which sounds very nice] without knowing what kind of exhaust system it is difficult to answer this question. deleting the cat will only sound good if you make other modifications as well.

Yes and no.Now I bet you're wondering why I've answered both yes and no. It may seem like I'm sitting on the fence on this one. But really I'm not. It all depends on what model car and what year the car is.So first to the yes answer. Yes punching out the cat will change the sound on some cars. Specifically cars that aren't naturally aspirated. The extra pressure of a turbo or supercharger will produce a whine with the cat punched out. Also vehicles with dual oxygen sensors ( with one sensor after the cat) will not run properly. This will produce a different exhaust note while the computer is trying to compensate for the off readings of the second oxygen sensor.Other cars with a single oxygen sensor will also produce a different exhaust note but not for the same reason. And the change won't be perceptible to your ears. But it will be different.Now for the exception. The no answer. A car with an already heavily modified exhaust. Like a single oxygens sensor car with a straight pipe and a glass pack muffler after the cat, the exhaust note won't change because of the free flow of the straight pipe and glass pack muffler.Other vehicles that have a resonating chamber after the cat also won't change in sound( unless it's a dual oxygen sensor system) because the after cat resonating chamber absorbs the extra exhaust flow and moderates the sound.So really it all depends on what your car had as a stock exhaust and it's configuration. While illegal to punch out your cat in most places in the United States, there are a few places left where it isn't. Those are the places where there is no emissions tests except for a visual inspection to see that all the components are there. Those places only inspect to see that the pieces are there and don't do actual exhaust emissions tests. Places like Indiana and Armstrong counties in Pennsylvania.Hope that helps :)PS. For anyone who wants to call bullshit on it not being illegal to punch out the cat. I live in Indiana county. They only require that the cat be installed on a vehicle required to have one, not that it actually be functional. Meaning that it's not illegal to do it. There's actually no law prohibiting you from doing it. Though it is frowned upon.

If I remove my catalytic converter on my car will it be loud?

Just loud enough to make it sound like it needs to be fixed... which it would. If you break the law by removing the converter, do you really want to attract the attention of police to your exhaust system? Removing the converter is not smart, but hoping the law notices is even worse... kinda like burglars who show off on youtube.

Back in the 70’s when catalytic converters were first introduced, they were really inefficient. Firstly, they were slapped onto old carbuteted engines as an afterthought to allow the old engines to pass emissions standards. They weren’t incorporated into the original engine’s design and choked down the exhaust that was designed to flow as freely as possible. Secondly, they were restrictive and removing them would really open up the exhaust and allow it to flow more freely, increasing the efficiency of your engine to a measurable extent.Nowadays, the design of both engines and catalytic converters has been greatly improved. Catalytic converters are not nearly as restrictive and the engines/exhaust systems are actually designed with them in mind. Taking one off of a modern car will have no measurable effect on power or economy if you remove it. The only difference you’ll notice is that it will set off a check engine light and that it won’t pass any emission test that applies. Do the yourself and the world around you a favor and leave it in place. Those things are there for a reason.