Catalytic Converter With O2 Sensor...

[Street]

Is there a way to remove a catalytic converter that has a o2 sensor right after it? What happens if you just replace the catalytic converter with a piece of pipe, whats the o2 sensor do?

[Team_DC-Derrick]

i hear now a days its a very, very bad idea to remove those converters... im in auto shop class in college right now and we are on that subject now. And the teach said it can be upwords of a 25,000$ fine.... i wouldnt risk it

[Ipod]

it'll set off the MIL light, and your car will not run right.. the PCM cant tell if your car is running to rich (too much gas) or too lean (not enough gas).. and i havent heard of a fine for 25,000 but you will get a fix it ticket and defiantly wont pass visual test (thats if they do an inspection)..

Edited May 19, 2009 by Ipod

[Street]

I live in South Carolina, theres no inspections or anything here.I also removed my check engine light last year cause it stayed on after everything was fixed, took it to atleast 7 diff places to have it checked, nothing wrong. Me and my cousin looked at my whole exhaust system earlier and noticed my car has 2 catalytic converters, one near the front with the o2 sensor after it the on down another one then my muffler. It would be alright to remove the second one or "gut" it wouldnt it? since its after the o2 sensor...

Edited May 19, 2009 by Street

[RamenNoodles]

All cars have both of those converters.

And You can remove the cat, your car wont freak out like it was said above. As long as you dont change any of the tuning on the car...

How do you think people do it all the time with their cars, you simply put in a test pipe instead of the cat. Your best bet is to weld flanges onto the test pipe so you can take it back off and put the cat back on when it comes time for emissions etc.

[CaptainzPlanetz]

I live in South Carolina, theres no inspections or anything here.I also removed my check engine light last year cause it stayed on after everything was fixed, took it to atleast 7 diff places to have it checked, nothing wrong. Me and my cousin looked at my whole exhaust system earlier and noticed my car has 2 catalytic converters, one near the front with the o2 sensor after it the on down another one then my muffler. It would be alright to remove the second one or "gut" it wouldnt it? since its after the o2 sensor...

I wouldnt do it, on the new cars there is an o2 sensor before and after the catalytic converters, and the computer moniters the difference between the pre o2 sensor and the post o2 sensor and by removing or gutting the converter the computer is gonna get confused and start messing with your air/fuel ratio(it is gonna think that you are running rich and is gonna lean the mixture, which is less fuel per air, which can then cause you car to miss, and you engine to run hot, now it might or might not be enough for you to notice, but down the line it can give you problems. Besides the way the EPA gets there way nowadays I wouldnt be surprised if inspections become required nation wide within the next 2-3 years.

Edit: Basically the o2 sensor tells the computer if your car is rich or lean, if it is rich meaning too much fuel per air, the computer sends less fuel to the engine, if it is lean more air per fuel, the sensor will detect the extra air left and feed more fuel to the engine. So for a gas engine the desired mixture is 14.7 parts of air to 1 part of fuel, this is the ideal combustion mixture, and the o2 sensor makes sure this mixture stays correct.

Edited May 19, 2009 by CaptainzPlanetz

[white4d96]

Losing the cat will cause a code reading 'insufficient catalytics' or something like that on OBD-II cars...don't ask how I know.

If you convert to OBD-I or before though (where the ECU doesn't look for that second O2 sensor) you can cut it out.

[Ipod]

All cars have both of those converters.

And You can remove the cat, your car wont freak out like it was said above. As long as you dont change any of the tuning on the car...

How do you think people do it all the time with their cars, you simply put in a test pipe instead of the cat. Your best bet is to weld flanges onto the test pipe so you can take it back off and put the cat back on when it comes time for emissions etc.

they use something called O2 simulator for the O2 sensor... but again... what do i know.. i'm just a student who spent that last 2 years at college going for my automotive analysis degree (be done in fall of '09)..

[CaptainzPlanetz]

they use something called O2 simulator for the O2 sensor... but again... what do i know.. i'm just a student who spent that last 2 years at college going for my automotive analysis degree (be done in fall of '09)..

I feel you man I just finished my Automotive training, about a year ago, right now I am finishing getting the rest of my ASE certifications, so I can be ASE master certified.

[white4d96]

All cars have both of those converters.

And You can remove the cat, your car wont freak out like it was said above. As long as you dont change any of the tuning on the car...

How do you think people do it all the time with their cars, you simply put in a test pipe instead of the cat. Your best bet is to weld flanges onto the test pipe so you can take it back off and put the cat back on when it comes time for emissions etc.

People do it by having a car that isn't OBD-II, or converting the engine management so it is pre-OBD-II.

Also: If you want to avoid hassle at visual inspections, just take a stock cat and gut the inside. They can't tell from the outside if you do it right.