removing cats.

[anton28]

Im going to be removing catalitic conveters on my 1999 gts. Will i through a code or will it effect the computer? If so what do i need to do to remove them with out any computer issues.

P.S. Smog is not an issue.

thanks guys.

[Snakester]

I believe that you need cat sims to keep from getting engine codes.

[red98RT10]

Hey! I just took out my cats today and was waiting to see if it would throw a code (according to Roe Racing, 1998 and later WILL throw codes), but it did not. Now...I have a VEC 1 and I dialled in a leaner fuel mixture and perhaps that is why it didn't do anything.

By the way, it sounds fantastic! Even from several miles away!!

[big-n-italian]

for the record - i took out the cats on my 97 without adding sims, and did not throw any codes.

[mntngts99]

Roe S/C, no cats, no sims, no codes.

[anton28]

i was told of getting sims for the 98+ cars. Even though it might not throw a code it should/will still mess with the fule/air mixture. With the vec-1 you can tune all of that but with the stock computer i might have a problem.

Can anyone recomend where i can get some o2sims?

I high flow cats now and borla exhaust i wonder what it will sound like with no cats.

[95Viper]

Casper Electronics. They plug right into the OEM connection, no wire cutting.

[Mccarlin]

I recently removed my cats as well and for 1 week now the car has not thrown an engine code at all (99). it does seem like the car is running rich though as the smell of gas is pretty bad.

Will buying 02 sims (even though i have all my 02 sensors still connected) help any with the air fuel since the cats were deleted? Will i have to remove my 02 sensors for this and replace them with the simms?

Thanks

[SNKEBIT]

The sims are for the rear O2 sensors. The sims will not help the gas smell. A vec.1 will tune out the rich mixture and take away most of the smell. These cars should be tuned w/ a vec. or something similar even if it's stock. They are not tuned very well from the factory.
If anybody needs a vec.1, I might have one for sale here very shortly. With the gauge, complete.

[Mccarlin]

The sims are for the rear O2 sensors. The sims will not help the gas smell. A vec.1 will tune out the rich mixture and take away most of the smell. These cars should be tuned w/ a vec. or something similar even if it's stock. They are not tuned very well from the factory.
If anybody needs a vec.1, I might have one for sale here very shortly. With the gauge, complete.

How much (if any) horsepower increase can you get from a Vac1 or Vac 2 tuning on a bolt on car?

[EllowViper]

Anyone use the mechanical 02 sims...the ones that simply move the 02 sensor anode out of the exhaust stream a bit via bacically a spacer? These only cost a few bucks and theoretically I can see how they would work.

[anton28]

SNKBIT

isnt the point of the o2 sim to fake the computer to think that the cats are still in place so the air/fule mixture is corect after removing cats.

If not what is the point of getting them.

[red98RT10]

SNKBIT

isnt the point of the o2 sim to fake the computer to think that the cats are still in place so the air/fule mixture is corect after removing cats.

If not what is the point of getting them.

that's what I always thought too.

[SNKEBIT]

SNKBIT

isnt the point of the o2 sim to fake the computer to think that the cats are still in place so the air/fule mixture is corect after removing cats.

If not what is the point of getting them.

Yes, that's right. I was just making sure people weren't using the sims in place of the front O2 sensors. With the cats removed, you are now not burning up the "extra" fuel that gets past the cumbustion cycle. (the stuff the cats would normally burn up. hence, why they are so freekin hot) These cars run a little rich from the factory. The vec. will help tune it so you cut back on the fuel load so you won't get such a huge gas smell from exhaust. I have a 94,I prolly gained about 10 h.p. from the vec. You will notice a difference if you have a stock car, I did.

[anton28]

what is the difrience between Vec1 and Vec2.