Cutout/dump
Thread Starter
Junior Member
Joined: Aug 2007
Posts: 20
Likes: 0
From: central ohio
Car: 1988 Trans Am GTA
Engine: TPI 350
Transmission: Auto
Cutout/dump
Hey guys
I have an 88 GTA. When I bought it it was cut off at the cat. I loved it but I needed something a bit more reasonable so I bought a used Boarla exhaust... got it put on professionally. The car lost alot of power and idles very rough now. It wants to stall until it is all the way warmed up. I know this Borla system had plates in the muffler the origonal owner could choose on depending on how lowed they wanted it. Im wondering if they put on the most restrictive one... any way to tell? Anyway. Im about fed up with this big V8 that feels like a V6 because of a muffler. could someone please give me some info on a fix and/or help on setting up a cutout?
My other question is where should I put the cutout. i dont have inspections so getting rid of the cat isnt a problem but Im wonderng how to bypass the 02 sensor. Hopefully you can see where Im going with this so if anyone has some ideas I would really apreciate it.
Thanks alot
I have an 88 GTA. When I bought it it was cut off at the cat. I loved it but I needed something a bit more reasonable so I bought a used Boarla exhaust... got it put on professionally. The car lost alot of power and idles very rough now. It wants to stall until it is all the way warmed up. I know this Borla system had plates in the muffler the origonal owner could choose on depending on how lowed they wanted it. Im wondering if they put on the most restrictive one... any way to tell? Anyway. Im about fed up with this big V8 that feels like a V6 because of a muffler. could someone please give me some info on a fix and/or help on setting up a cutout?
My other question is where should I put the cutout. i dont have inspections so getting rid of the cat isnt a problem but Im wonderng how to bypass the 02 sensor. Hopefully you can see where Im going with this so if anyone has some ideas I would really apreciate it.
Thanks alot
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Why would you want to bypass the O2 sensor? It's up in the exhaust manifold, anyway, nowhere near the cat.
Thread Starter
Junior Member
Joined: Aug 2007
Posts: 20
Likes: 0
From: central ohio
Car: 1988 Trans Am GTA
Engine: TPI 350
Transmission: Auto
Re: Cutout/dump
I didnt know this. As you can tell im knew to cars. I was just looking at my cat and there was a smnall tube going into it so I made the assumption that it was the oxygen sensor. That explains alot
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
That's the Air Injection Reaction (typically abbreviated as A.I.R.). Fresh air is pumped into the cat to help it do its job better. It doesn't cost any power, and does help clean up the exhaust. If you remove the cat, you'd probably better remove that as well, which will reroute your belt. Starts getting involved then.
I take it you didn't get the disk set with the Borla. I believe those can be purchased separately.
I take it you didn't get the disk set with the Borla. I believe those can be purchased separately.
Thread Starter
Junior Member
Joined: Aug 2007
Posts: 20
Likes: 0
From: central ohio
Car: 1988 Trans Am GTA
Engine: TPI 350
Transmission: Auto
Re: Cutout/dump
The only way I would have the disk is if someone who owned the exhaust before me put it on. Im about to throw this whole Borla POS out though. I never would have geussed it would rob me this much torque. I geuss my ultimate goal is to build up my 350 to between 300 and 350 hp but I don't want to do this without figuring out the exhaust problem.





