Emissions and Noise-First Cat. Removal ?

Benesesso · 04-18-2006, 09:54 PM

Need some info about what to expect if I remove the first cat. conv.--the one close to the turbo. How much will the noise and emissions increase?

ddmcse · 04-18-2006, 10:13 PM

mine has been out for a few years and i pass emissions ( i think 3 times now or roughly 5 yrs)
i never noticed any noise, just FCO.
I don't have any actual numbers of how much emissions increase.

Benesesso · 04-18-2006, 10:56 PM

FCO? New one for me. The small size of the cat. makes me think it doesn't flow well, but I haven't looked inside.

I did take a die grinder to the elbow and enlarged the most restrictive areas. Took me ~15 min--easier than porting a small-block Chevy port.

ddmcse · 04-18-2006, 11:15 PM

when you go from stock to modified at some point you'll start hitting Fuel Cut Off FCO. we're talking turbo supra.
once you let the car start to breathe the computer will realize that there is way more air flowing than normal and you'll throw a error "code 34"and at the same time you will shit your pants
because the EFI will cut off fuel for just a fraction of a second . now picture this ...

you are punching it hard and the car feels real nice and it's pulling good , you're smiling big .. then all the sudden WHAM ! it's like you hit a car but there's none in sight
if you're not expecting it you will shit your pants .

you will quickly learn either
A:
not to punch it so much

or

B:
figure out you need to spend more money to get rid of that shit

Benesesso · 04-18-2006, 11:33 PM

I don't want to raise the HP that much. The horror of losing another HG is the big factor. I'm still getting the car back together-it's been over a month. I'm amazed that anyone can do this job in less than a week.

~10 psi is enough--at least for a few years.

ddmcse · 04-19-2006, 12:11 AM

dude you're gonna hit FCO at some point
and i know exactly what you mean .. that engine has earned your respect.

04-18-2006, 09:54 PM	#1
Benesesso 3" Exhaust Join Date: Nov 2005 Location: Phoenix, AZ Posts: 145	Emissions and Noise-First Cat. Removal ? Need some info about what to expect if I remove the first cat. conv.--the one close to the turbo. How much will the noise and emissions increase? __________________ "You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein 1988 and 1990 Turbo Supras

04-18-2006, 10:13 PM	#2
ddmcse 500whp yet? Join Date: Jun 2005 Location: CT U.S.A. Posts: 966	mine has been out for a few years and i pass emissions ( i think 3 times now or roughly 5 yrs) i never noticed any noise, just FCO. I don't have any actual numbers of how much emissions increase. __________________ 300+ RW HP Dyno run, jdm,mod turbo,3"exh,electfan,greddyboost Blown HeadGasket info My Supra KiXGaS

04-18-2006, 10:56 PM	#3
Benesesso 3" Exhaust Join Date: Nov 2005 Location: Phoenix, AZ Posts: 145	FCO? New one for me. The small size of the cat. makes me think it doesn't flow well, but I haven't looked inside. I did take a die grinder to the elbow and enlarged the most restrictive areas. Took me ~15 min--easier than porting a small-block Chevy port. __________________ "You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein 1988 and 1990 Turbo Supras

04-18-2006, 11:15 PM	#4
ddmcse 500whp yet? Join Date: Jun 2005 Location: CT U.S.A. Posts: 966	when you go from stock to modified at some point you'll start hitting Fuel Cut Off FCO. we're talking turbo supra. once you let the car start to breathe the computer will realize that there is way more air flowing than normal and you'll throw a error "code 34"and at the same time you will shit your pants because the EFI will cut off fuel for just a fraction of a second . now picture this ... you are punching it hard and the car feels real nice and it's pulling good , you're smiling big .. then all the sudden WHAM ! it's like you hit a car but there's none in sight if you're not expecting it you will shit your pants . you will quickly learn either A: not to punch it so much or B: figure out you need to spend more money to get rid of that shit __________________ 300+ RW HP Dyno run, jdm,mod turbo,3"exh,electfan,greddyboost Blown HeadGasket info My Supra KiXGaS

04-18-2006, 11:33 PM	#5
Benesesso 3" Exhaust Join Date: Nov 2005 Location: Phoenix, AZ Posts: 145	I don't want to raise the HP that much. The horror of losing another HG is the big factor. I'm still getting the car back together-it's been over a month. I'm amazed that anyone can do this job in less than a week. ~10 psi is enough--at least for a few years. __________________ "You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein 1988 and 1990 Turbo Supras

04-19-2006, 12:11 AM	#6
ddmcse 500whp yet? Join Date: Jun 2005 Location: CT U.S.A. Posts: 966	dude you're gonna hit FCO at some point and i know exactly what you mean .. that engine has earned your respect. __________________ 300+ RW HP Dyno run, jdm,mod turbo,3"exh,electfan,greddyboost Blown HeadGasket info My Supra KiXGaS