best way to remove cats?

[Cloudsurfer]

There will be zero gain to be had by removing the cats unless you are also upgrading the headers to some that flow well. The rear muffler isn't actually that restrictive, but the factory headers are horrible.

As to CELs, you will get a catalyst inefficiency error due to the lack of difference in pre and post cat O2 readings. You can either flash your DME to RoW program with a PST2 (which ignores the secondary O2s), or you can try locating the secondary O2s after a spark plug defouler, which may work.

Patrick

[Boxtaboy]

This may not matter in your state, but if Illinois does require state inspections, wouldn't the CEL trigger prevent you from passing any inspections? Here in NY/NJ, if you have a CEL light, and then try to mask it by disconnecting your battery and resetting the light, you still won't pass the inspection because your readiness codes will not have reset until you drive a certain amount of drive cycles, and by then, your CEL would reappear. Just curious.

[djomlas]

i just passed the inspection, i had a CEL few days prior, and just turned it off with OBD reader...they dont really care here.
i passed inspection with straight pipes on my other car 3 yrs ago as well , pretty neat

[Brucelee]

The issue I see is that if you CEL is always on and you develop an additional code, you won't know it.

It seems to me that this could be an issue, no?

[djomlas]

you make a good point,
i have my OBD reader plugged in at all times, so pushing the "read" button every now and then should not be that hard.

also, if i do put the test pipes on there, can i just plug the O2 sensor in there? or does that not even matter now that the cats are gone and that the reading off of them will be wrong?
just triyng to understand all this...

DJ

[chaudanova]

Hey DJ, check out this thread that MTS just made:

http://986forum.com/forums/showthread.php?t=18467

The notable part was:

"I did with and without dyno runs with the Fabspeed 2nd cat bypass pipes. The car is a 2004 Boxster S Special Edition with 17k miles (de-snorkled). The baseline runs showed 228 whp. With the bypass pipes installed, the dyno showed 237 whp with a negligible/no change in hp curve. Given all the slight variations run to run, etc, I'd say the Fabspeed claim of 8 hp for using the pipes appears to be accurate, at least on my car."

He gained 9whp on the dyno... not too shabby!

[Allen K. Littlefield]

Do you know if the Fabspeed bypass pipes have a bung for the second oxy sensor?

AKL