MTB

Car is only for DE but I do drive it to and from tracks. For 3+ hours distance, I tow it.
I am planning to upgrade the cat, but debating either 200cells x pipe or x pipe bypass. I installed the 200cells x pipe in the C4S, engine breathes & sounds better. Since I do not drive the GT3 on the street, so I thought of cat bypass. Any comments welcome!

P.S. OEM headers and cargraphic mufflers

Michael

mooty

no cat on mine.

996FLT6

^same here.
Mike

cfjan

I assume with cat bypass there will be CEL? Or you guys had the computer re-programmed or run the sensor extender?

SH || NC

With cat delete don't you get some gas fumes in the car?

I am also interested in maybe a 200 cell setup; I also had a setup on my C4S and liked it

DHI

I must be getting old.
After living with a cat-less track oriented street driven Rx7, I found the snowmobile smell to be increasingly obnoxious.
I think a 200 cell cat to be a more elegant hi performance option if there any street driving involved.

mooty

^ only the car behind you smell the fumes, no.
i haven't smelled anything..

i have both O2 sensor still. one exposed to outside air.
no CEL, but i only drive on track. i was told at wot, you wont get cel. if you start town driving, you might. that's what i heard. i dont know if it's true.

DHI

Story...
Years ago, I went to pickup a date in a cat-less rx7, figuring she was the type who would appreciate a raw sportscar.
At the door, she took a few whifs, and asked me WHEN I had started smoking.
;-)

FFaust

Is there requirement for e-testing in BC?

I have hi-flow cats and the P dealership tried everything to get the car to pass emissions when I bought it a few months ago. Took a couple of weeks but in the end, they ended up having to install stock cats for test...

MTB

Is Cat bypas has better performance than high flow cat?

I liked the 200 cell set up in my 4S but cat bypass is 1/3 the price!

I planned to use the O2 simulators. If there is cell, I can use the Duramatric.


Yes, we have "air-care". And it is only for car with annual insurance. I only buy temp insurance when I drive it.

cfjan

I assume Durametric can reset the CEL but can it actually program it so CEL does not come on? Because for state emission, they look for CEL, but your ECU needs to have the "ready status" ready.. i.e., if you just reset the light, then the ready status will show as not ready. You need to drive the required 100 miles or so (depends on how you drive it) to have the ECU ready.

SH || NC

No doubt its cheaper; just a section of pipe vs. expensive cat materials.

We have annual inspections with an OBD2 hook up, and I'm not willing to swap the pipes in an out; I'll just get a 200 cell setup and be done with it. If my GT3 was track only, and de-registered the car for the street, then sure.

911SLOW

With oem headers and a free flowing muffler at oem diameter piping,

the gain averages are:

200cell cats +6HP
100cell cats +9HP
no cats +12HP

the 100 cell and cats by pass are louder than 200 cell and will fail most emmisions tests
200 cell no check light never
the CEL can appear after one day or a year after depending on driving conditions
don't leave the after cat 02 sensors on open air make sure they are in even if the voltage reading is wrong
cel light can be bypassed with dme upgrade or proper extensions on O2 sensors

what smell you are talking about? It smells wonderful although i still prefer nitromethane aroma : )

SpeedGT3

Are you talking about a GT3 ?
If you DONT run the CAT and only the bypass pipe, you WILL lose HP and TQ.
I know this for a fact. We did many back to back dyno runs.

These motors (low compression) need back pressure.

mooty

U need to do "something with muffler"

I have no cat and hsve bk to bk to bk test same day same Dyno by swapping pipes muffler on site. I assure u there's gain in
Hp and tq. Not much. But gain for sure.

And the Wt loss is amazing. Cheapest Wt loss route.
And dint bother with expensive car graphic and such. Think cheap real cheap mufflers. No not burns. Cheap really cheap stuff.

Can't divulge more. My tech would kill me