high flow cat?

[97sonoma]

Ok, well I went to the muffler shop to get an estament on my exhaust. I asked if i went up there with my cat cut off if they would just make the exhaust headerback (without the cat) and he said i cant because of the o2 sensor. Well my friend has an s10 without a cat. his is older so i doubt it has a o2 sensor? how can i get around this?

[OverBoardProject]

The oxy sensor is before the cat, so I can't see that effecting the computer at all. Although I might be wrong.

It's illegal for the muffler shop to remove your cat though, so he did the right thing. If he did, and got caught the fine is most likely pretty high. In some states they would probably shut him down for a while

You can however buy a piece of pipe, cut the cat out, and just clamp the pipe in place.

[97sonoma]

alright, well i guess i will just get my exhaust on and if it doesnt sound like i want then ill just cut the cat off after the 02 sensor and put a test pipe on?

[chcknugget]

I think all 96+'s have sensors after the cat to make sure they're there. If the cat's taken out it will throw a code, you will get a light on, and your truck will go into no power and no efficiency mode. I hear summit sells trick sensors that tell the computer the cat is there and then you would be set.

['89sdimeblazer]

Ive also heard talk of the O2 trickers take a look into that.

[Mikado14]

Originally Posted by 97sonoma

Ok, well I went to the muffler shop to get an estament on my exhaust. I asked if i went up there with my cat cut off if they would just make the exhaust headerback (without the cat) and he said i cant because of the o2 sensor. Well my friend has an s10 without a cat. his is older so i doubt it has a o2 sensor? how can i get around this?

Any Blazer with ANY type of fuel injection will have an O2 sensor. Your friends must be carbureatored.

If you have a '97 Sonoma (guessing from your name) you will have four (4) O2 sensors. Count em. One on each bank, one pre-cat and one post-cat. If your in the state of Florida (guessing from your profile), any mechanic who tampers, alters or disables any emission control system is subject to a fine and lose of inspection privileges if he/she is so licensed. Some states have fines of $10,000.

If you really want to change the sound, go to a high flow cat and a low restriction muffler.

[chcknugget]

However pre 96 vehicles do not have the sensor after the cat so I hear.

[BiGwiLLswiLLy]

heres the deal 95 and older have 1 o2 sensor before the cat so if u remove it no light will show 96 and newer have OBD2 which has 2 O2 sensors 1 before n after the cat if u remove it u will need a trick o2 sensor to get it to pass emissions...the only cars with out o2 sensors are pre-smog years i belive that was 73 cars n older

[BiGwiLLswiLLy]

o and 95 n older cars if u remove the cat n run it on the dyno for emissions it'll fail but with OBD2 96 n newer all u have to do is trick the computer not to throw any codes n it'll pass cause u dont run those cars on dyno's no more they jus plug into a comp n check for codes n make sure the light works!

[Mikado14]

Originally Posted by BiGwiLLswiLLy

heres the deal 95 and older have 1 o2 sensor before the cat so if u remove it no light will show 96 and newer have OBD2 which has 2 O2 sensors 1 before n after the cat if u remove it u will need a trick o2 sensor to get it to pass emissions...the only cars with out o2 sensors are pre-smog years i belive that was 73 cars n older

"heres the deal 95 and older have 1 o2 sensor before the cat so if u remove it no light will show "

Oh really? Pulling the only O2 sensor will not throw a code? So when the ECM goes into closed loop how will it meter fuel? It will go into limp mode and fuel economy and performance will suck.


"96 and newer have OBD2 which has 2 O2 sensors 1 before n after the cat"

Don't think so on that one either. There will be four, one on each down pipe, that is two on a 4.3L and then the pre-cat and post-cat. When I went to school, that added up to four. At least on a '96, '97 and '98 with a 4.3L.

"the only cars with out o2 sensors are pre-smog years i belive that was 73 cars n older"

When the s-10 came out they were carburaetored. No O2 sensor and that was '82 or '83. The 2.8L carb did not have an O2.

[Mikado14]

Originally Posted by chcknugget

However pre 96 vehicles do not have the sensor after the cat so I hear.

'95 and older that have CPI on the 4.3L have one (1) O2 sensor. And if you keep going back far enough, they are not even Heated.

[dmbrisket 51]

whats it matter? it doesnt, the fact is his has a post cat sencor, you can get an o2 cheater from jegs and i beleve summit, as long as the cheater only disables the one sencor i say go for it, if it dissables all of them i wouldnt do it because then if you get a gunuine problem you will not know it

[rlith]

Originally Posted by Mikado14

'95 and older that have CPI on the 4.3L have one (1) O2 sensor. And if you keep going back far enough, they are not even Heated.

No, 95's have 2-3 o2 sensors depending on the ECM... For instance, mine has 3, 1 on the down pipe, 1 before the cat, 1 after the cat, some just have 1 before and 1 after...

[Mikado14]

Originally Posted by 97sonoma

Ok, well I went to the muffler shop to get an estament on my exhaust. I asked if i went up there with my cat cut off if they would just make the exhaust headerback (without the cat) and he said i cant because of the o2 sensor. Well my friend has an s10 without a cat. his is older so i doubt it has a o2 sensor? how can i get around this?

Here's your answer, post cat cheaters:

http://www.jegs.com/cgi-bin/ncommerc...28&prmenbr=361

[BiGwiLLswiLLy]

first of all u wont unplug a O2 sensor when its before a cat...hes removin the cat not the o2 so ur wrong n there are 2 o2 sensors on a 4 cyl so youre wrong again dont critize me if u dont know go back to school