Cat Sensor Delete

**supercopone** · 11-04-2009, 08:28 AM

I went by the exhaust shop the other day and was looking at getting a install done. KY Speed thats on here has a sale going on and I think im gona get one from him. I asked about deleteing my cat and he told me he could not do it, he said something about a sensor that was there. He was busy so i did not take up much of his time, but dose anyone know what he was talking about?

**Y2KPewterSS** · 11-04-2009, 09:04 PM

LS1 fbodies have 4 oxygen sensors, 2 in front of the cats, and 2 after the cats. The rear 02 sensors monitors what the emissions are doing, they are not necessary to have and are removed when you do long tubes anyways. The sensor can go adios, its done all the time. Removing it will throw an SES light, but won't harm performance. Just get the codes turned off by a tuner once the rear 02 sensors are removed. The guy you talked too, probably was just not comfortable removing your cat all together and that was his excuse for not doing it.

**0rion** · 11-04-2009, 09:24 PM

99.999% of the shops out there won't do it......they're looking at extremely hefty fines if they get caught.

**Smittro** · 11-04-2009, 09:30 PM

Originally Posted by 0rion

99.999% of the shops out there won't do it......they're looking at extremely hefty fines if they get caught.

Same here in PA. I deleted my cat but have to put it back on for inspections. Pa law also requires it to be @ least visible in the counties that don't have emi testing.. My z34 is exempt from emi but still had a high flow on it for the law..

**ssgtwalsh** · 11-06-2009, 02:54 PM

i am not running cats nor muffs and dont have any problems. now my cam pos sensor is another problem since i am running a huge cam. lol

**supercopone** · 11-06-2009, 07:21 PM

So you just tie up the wires and let it at that?

**ssgtwalsh** · 11-07-2009, 05:18 AM

just get your pcm flashed so it doesnt keep sending a code and doesnt make the engine light come on, but yeah thats basically it. the rear sensors are not really neccasary for anything.

**supercopone** · 11-07-2009, 03:57 PM

what about the front ones?

**jsremmos** · 11-07-2009, 10:15 PM

still need the front ones...

**supercopone** · 11-07-2009, 11:00 PM

hmmmm,

**ssgtwalsh** · 11-08-2009, 11:16 AM

the front ones need to stay in. but you can get rid of the rears.

**ryan_gilson** · 11-15-2009, 09:44 PM

If you don't want to go threw the trouble of getting your computer re-flashed I remember seeing somewhere an O2 elininator. As i understand it is a chemical reaction that produces small amounts of electrical curent. This would requier a power sourse. If you have a had time finding them on the internet hook up a multi meeter to your O2 sensor set start reducing the setting on the meeter untill you get a good reading and then you can rid something up quite easy to trick the computer at the same curent values. I am not sure if it runs on curent or volts. the equasion is V=IR. Voltage = Curent X Resistance. So say you are using your 12 volt car battery (12-14Volts) and are shooting for 16mA. you would need 750 Ohms of resistance between your positive terminal of your battery and the hot lead of the O2 sensor. Then connect the other line to chassas ground. If the O2 goes by voltage you would need to do a voltage devider cuit. Same basic Idea just measure the resistance of the leads going to your computer from the O2 then make a ratio of resistors from the positive lead of your battery. Make sure you cheek voltages and curent readings whail the car is running so you have the right starting point for your math. If it ends up being voltage you can look up the formula just about anywhere. I do not have the correct keys on this computer to put it in wrighting but it is quite simple. Good luck. You may just want to get it flashed i personaly like doing everything my slef and i would definitly do this one becuase it would only cost $2-$5 at radio shak.

**Smittro** · 11-15-2009, 10:00 PM

Rear 02's can be tuned out, and are not nessasary for drivablity or engine operation. IMHO don't even piss with them unless you need the cat/s for your state. Have the code cleared and move on to you next mod..

**supercopone** · 11-15-2009, 10:48 PM

Originally Posted by ryan_gilson

If you don't want to go threw the trouble of getting your computer re-flashed I remember seeing somewhere an O2 elininator. As i understand it is a chemical reaction that produces small amounts of electrical curent. This would requier a power sourse. If you have a had time finding them on the internet hook up a multi meeter to your O2 sensor set start reducing the setting on the meeter untill you get a good reading and then you can rid something up quite easy to trick the computer at the same curent values. I am not sure if it runs on curent or volts. the equasion is V=IR. Voltage = Curent X Resistance. So say you are using your 12 volt car battery (12-14Volts) and are shooting for 16mA. you would need 750 Ohms of resistance between your positive terminal of your battery and the hot lead of the O2 sensor. Then connect the other line to chassas ground. If the O2 goes by voltage you would need to do a voltage devider cuit. Same basic Idea just measure the resistance of the leads going to your computer from the O2 then make a ratio of resistors from the positive lead of your battery. Make sure you cheek voltages and curent readings whail the car is running so you have the right starting point for your math. If it ends up being voltage you can look up the formula just about anywhere. I do not have the correct keys on this computer to put it in wrighting but it is quite simple. Good luck. You may just want to get it flashed i personaly like doing everything my slef and i would definitly do this one becuase it would only cost $2-$5 at radio shak.

My eyes are bleeding and my head hurts...too much info

**ryan_gilson** · 11-16-2009, 03:17 PM

Sorry. jsut thought it may help. I hate spending money or having somone else work on my cars if I can avoid it. It is a bit of a hassle but if you don't have the money or time I don't think is a half bad way to go. Sorry for draging on like that.