cats

[dramo1]

is it ok to get rid of the 2 small cats on my 86 coupe and just leave the one large cat on ..have a flowmaster cat-back 2 on..what effect would this have on performance and sound..

 

[sxyvet]

is it ok to get rid of the 2 small cats on my 86 coupe and just leave the one large cat on ..have a flowmaster cat-back 2 on..what effect would this have on performance and sound..

hi there mate,
im not sure in usa about the two cats being on, but i took my old clogged of ones off and replaced them with a high flow magnaflow cat instead and along with magnaflow rear straight thru mufflers with lt 1 tips andf it made a big diiference in power, sound, looks!
the old clogged up cats were restrictive and now the motor has a real growl to it!
now once i get my pacemaker tuned long headers in a week or so it should really sound great plus extra performance again!
thanks
glen
australia

 

[KANE]

is it ok to get rid of the 2 small cats on my 86 coupe and just leave the one large cat on ..have a flowmaster cat-back 2 on..what effect would this have on performance and sound..

Technically... removing the catalytic perverters is illegal.

With that said, I ran a TPI swap (complete MAP system with speed-density OEM computer) on a 78 with sidepipes. Yup- no cats. Your 02 sensor is BEFORE the cats. I never had any problems with the ECM reacting to no cats. As long as the other sensors are happy, the car doesn't know it doesn't have a cat.

However, this ISN'T true with OBD-1 /2 cars... they will light a PCM code in a second if they don't recognize lower unburnt 02 emissions between the fore/aft 02 sensors.

Back to your 86...

If you want to be "to the letter of the law" legal... go with a high-flow cat.

If you want to somewhat legal...two high-flow cats, 2" 1/2 to 3" pipe, equal length headers, a cross-over pipe, and some nice mufflers works the best.

 

[Agent 86]

I had mine cut out at an exhaust shop and replaced with pipe. No complaints