Cats and CO2

[Cody the Roady]

I have a 1987 Chevy Silverado, 350 TBI, 700r4. Doing a mid level restoration, and one thing I want to do is new exhaust. I'm keeping the original manifolds (no serious engine/HP upgrades), and want dual exhaust, Flowmasters (maybe 50 Delta Flow), straight back with turn downs. Several people have said to get rid of the catalytic converter, since the truck is the age it is, and it's not an inspection issue here where I live. However, someone has mentioned to me that running this 350 TBI without a cat will throw off my computer readings and make the truck run worse. Anyone had experience with this? Thanks.

[Captkaos]

The 02 is in the manifold and is upstream of the cat.  You should not see any issues with removing it.
My 87 was like that since I bought it in 2006 and was not changed until I put an LS in it 2 years ago.

[LTZ C20]

As Capt stated, you should be fine, I have an 89 TBI on my truck, O2 sensor is before the cat, removing the cat won't hurt anything, I have no cats, true duel exhaust and no crossover on my truck, runs no problem at all.

[Captain Swampy]

The only problem I've heard of is free flowing exhaust lowers the exhaust temp low enough the o2 sensor won't work. tbichips.com has 3 wire heated o2 sensor kits.

[AZ87V10]

I had the cat eliminated and ran straight through when I had the exhaust on my 87 replaced. It's all new from the stock manifolds back to the tail pipe. Now, mine's routed exactly like the factory just minus the cat and my truck runs great! Although I have a leak from the right side manifold that's either a blown gasket or cracked manifold. I also rebuilt my TBI and since then haven't had any stalling issues; a topic for another recent thread on here! You shouldn't have any issues eliminating your cat. Like I said, that's how my truck is and it runs fine. No codes or anything either. Gets up to temperature just fine and no loss of power. My engine is all stock too.

[VileZambonie]

If you are keeping the manifolds you won't have any problems. What are you asking about CO2?

[Cody the Roady]

Great answers, guys. Thank you so much. Regarding the CO2 question, it was just something a mechanic had mentioned to me. But nobody else had said anything about it. My son wants me to go with Flowmaster 40 Series. But then again, he's a teenager, and trucks can't be loud enough for him. I'd like to be able to carry on a conversation with my wife. 

[rich weyand]

I have the 40s, and we carry on conversations.  But you can't mumble.  WHAT?  I SAID, YOU CAN'T MUMBLE.

[Cody the Roady]

I just got a visual of Pee Wee Herman, standing on a table in a biker bar with an enlarged ear. Good one, Rich.

[LTZ C20]

I have dual Flowmaster Super 44s, I can tool along at 60mph, and have a normal conversation, using our INSIDE VIOCES. lol

[Cody the Roady]

The shop here in town has a really good reputation (183 Mufflers, Lockhart, TX). I've read quite a few comments on-line from guys who have driven almost 100 miles to use him. I know that when we talk, he'll hear all my concerns and set me up just fine. It's nice to have people out there that take the time to explain things to you. Such a rare trait these days...