Running without a catalytic converter

[allout13]

Anyone on here running without a cat?


I'm looking to get an exhaust for the spyder, and let's face it, high-flow cats are expensive. lol My car is registered in Bartow county, so I don't have to pass emissions.


From what I've read I'll get a very slight performance boost, and my fuel economy will be improved if changed at all. I've also read that there can be huge fines for running catless. Has anyone ever been fined for running without a cat?


and as far as check engine lights go, one of these lil guys ought to help me get around that:
http://www.kamispeed.com/TiTek-Mecha...it-uni-001.htm


tell me your experiences both positive and negative

[WhiteAccord]

Im currently not running a cat. Straight 3inch w/ a lot of backfire(Getting Tuned Soon to Compensate).

Yes you will have a boost increase, and a good chance in power increase, and possibly check engine lights.

Also as for the fuel economy, sure maybe... If you can keep your foot off the gas pedal.

LOL at that CEL Fix Adapter price... You can get one at NAPA for 8 bucks.

[allout13]

Im currently not running a cat. Straight 3inch w/ a lot of backfire(Getting Tuned Soon to Compensate).

Yes you will have a boost increase, and a good chance in power increase, and possibly check engine lights.

Also as for the fuel economy, sure maybe... If you can keep your foot off the gas pedal.

LOL at that CEL Fix Adapter price... You can get one at NAPA for 8 bucks.

not too worried about how big gains will be or not. running without a cat is less expensive than with a cat. lol so as long as there are no negative consequences, I'm all for it.

Thanks for the headsup on the CEL fix adapter!

[silversol]

A cat helps with fuel economy not hurt it fyi

[.blank cd]

A cat helps with fuel economy not hurt it fyi

Not much if at all. I've run this same motor setup daily with and without a cat and haven't seen any noticeable mileage gains or losses. All a cat does is scrub the exhaust and create minimal back pressure. Depending on your setup, back pressure can be a good or a bad thing

[allmotor-teg]

i dont have a cat on my car and i has not giving me any problems, its kinda loud but no fines( knock on wood) where i live they dont have emission so.

[Durtie]

I prefer a cat. I don't like my car very loud. I prefer a nice tone. Hell, when I take out the hatch cover, the pitch sometimes hurts my ears. I couldn't imagine what it would be like without a cat.

[green91]

Ive got 3" turbo back exhaust no cat on my honda no issues. On 4cyl n/a it usually makes them sound raspy, may want to get a resonator welded in place.

[1moreaccord]

tell me your experiences both positive and negative

Ran without one for 1.5 years, almost no difference except more pollution. No trouble with legality, honestly detectible only with emissions hardware. I recommend a bolt on straight pipe. When you try to resell (Buyer may live in an area that requires emissions), ability to pass emissions is critical and if it's bolt on you can just replace it. Catalytic converters are expensive.

..sigh.. ok :

A cat helps with fuel economy not hurt it fyi

QFT!

Not much if at all. I've run this same motor setup daily with and without a cat and haven't seen any noticeable mileage gains or losses. All a cat does is scrub the exhaust and create minimal back pressure. Depending on your setup, back pressure can be a good or a bad thing

You're right, not a big difference, but many new cars run an o2 sensor, pre-cat / primary cat, o2 sensor, post-cat / secondary cat to modulate ECU controls on fuel delivery etc.

i dont have a cat on my car and i has not giving me any problems, its kinda loud but no fines( knock on wood) where i live they dont have emission so.

Catalytic converters contain only "honey-comb" shaped fiber that removes pollutants from exhaust, from my understanding it has no sound deadening /muffling capabilities and shouldn't affect how loud your exhaust is, as it didn't on my car.

Also the only way someone is going to prove you don't have a Cat is physical inspections accompanied with an exhaust test. There are symptoms, but can't be proven without what I mentioned - Plus I think running without a cat is the absolute bottom of the barrel of illegal pickin's when it comes to the municipal powers. (Read: They don't care!)

[green91]

Its actually a felony to modify any emissions control equipment for on-road usage if you want to get legalistic. There is also a visual inspection so if you have a test pipe bolted in or even a straight pipe welded in, its automatic failure.

Post cat o2 aren't used for fuel trim calculation in ECU on obd2 cars.

[1moreaccord]

Its actually a felony to modify any emissions control equipment for on-road usage if you want to get legalistic. There is also a visual inspection so if you have a test pipe bolted in or even a straight pipe welded in, its automatic failure.

Correct as is a plethora of other car modifications including HID's, different spec bumpers, performance engine parts, lights, lowering the car even an inch.

In which case - Just knock out the internals and you pass visual inspection! But if your getting an inspection at all you better have a Cat on as will not pass anways!

Post cat o2 aren't used for fuel trim calculation in ECU on obd2 cars.

There are always exceptions, but again you are correct!

[thesammy]

Hi flow cats are $100 or less, metalcore cats are like $120. I had a hi flow on my NA set up and have a metal core for turbo. For NA, it did help with sound in my case, and I live in an emissions county. I also park in a garage, and letting the car warm up for a second without a cat can really leave the place smellier than no cat.

They also sell "non" or "anti" catalytic converters on eBay, if you did live in emissions county. It's $40 or $50 and is a straight pipe with a cat casing, nice for turbo set ups that don't want restriction. Lol

If you're NA, a cat won't rob much power, helps give a nice tone, and doesn't kill the people driving behind you. Then again, I have a cut out for when I want to bypass my cat. Lol

[thesammy]

Also, that o2 sensor spacer you linked, you can also buy a pack (comes with 2) spark plug non foulers at autozone, made by a brand called "HELP" and part number is 42002, drill one out to 1/2" and bolt them together, bolt the sensor to them, and bolt that to your secondary o2 bung, which spaces it out enough to where your CEL wont come on.

Alot of new ppl always ask the same kind of question. How do i fix the engine light after installing a header? When this light comes on from the installation of a new header/midpipe, be aware that this has no effect on the performance of your car. its just a stupid reminder that the o2 (oxygen) sensor is finding a problem caused by when you removed or did something to the stock catalytic converter.

STEP 1
-purchase 2 spark plug anti foulers at your local auto parts store
-18 mm size
-made by HELP brand / part number 42002



STEP 2
-disconnect the negative terminal on your battery. this will reset your ecu
-take one of the anti foulers and drill out its center using a 1/2 bit ,
-this will increase its hole size and allow your stock o2 sensor to fit







STEP 3
-screw the drilled spark plug anti-fouler on top of the original
-in case you need to remove the foulers, use some kind of anti-seize on the threads





STEP 4
-unscrew your stock o2 sensor and place your anti-fouler fix in
-use anti seize on the threads -clean your cell (by wiping it off with a paper towel)






STEP 5

-reinstall your o2 sensor
-reconnect your battery (your ecu is reset)
-you have just solved the problem of the annoying light

At the end of everything, it should look like this in the same order ( o2 sensor-->1/2 drilled fouler--> undrilled fouler-->header or exhaust.

[allout13]

thanks for all of the input guys!

the car will NOT have to pass any inspection. I was just wondering if it was something I should worry about should I get pulled over an a cop take a look under the hood. Sounds like I don't have much to worry about.

[thesammy]

thanks for all of the input guys!

the car will NOT have to pass any inspection. I was just wondering if it was something I should worry about should I get pulled over an a cop take a look under the hood. Sounds like I don't have much to worry about.

Not in GA, never heard or seen that happen. Cali is usually the only ones who have to deal with stuff like that.

[Drummerboy]

Is your cat under the hood? lol.

I don't have a cat. Just a resonator and muffler. I get a cool crackle on decel, lol. You shouldn't have any issues with police.

[allout13]

Is your cat under the hood? lol.

I don't have a cat. Just a resonator and muffler. I get a cool crackle on decel, lol. You shouldn't have any issues with police.

yes, yes it is...

[allmotor-teg]

thanks for all of the input guys!

the car will NOT have to pass any inspection. I was just wondering if it was something I should worry about should I get pulled over an a cop take a look under the hood. Sounds like I don't have much to worry about.

you should be alright.