Catalytic converters: does your square have them?

Does your square have a catalytic converter?

  • yes

  • no

  • yes, but only because I couldn't get a sticker/plate without them.

  • no, but only because I'm too lazy/cheap to change what the previous owner did.

  • no, because my truck didn't come with them.


Results are only viewable after voting.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

RecklessWOT

Full Access Member
Joined
Feb 20, 2015
Posts
2,548
Reaction score
4,744
Location
New Hampshire
First Name
Kevin
Truck Year
1987
Truck Model
V10 Suburban Silverado
Engine Size
350 TBI
My 87 had a cat on it for 28 years. Then I got my hands on it and a few weeks later that useless hunk of weight and exhaust restriction was tossed in the scrap pile. Shortly thereafter I removed the air pump and EGR as well. No emissions testing on vehicles that old in my state, and as far as I know any other state I have ever been to doesn't care either as my truck isn't registered in their state (and to the best of my knowledge most states have similar age based exemptions anyway).

Generally I hate cats on anything. My DD came with 3 cats on it, it now only has one high flow cat solely for the purpose of noise reduction, catless Subarus sound like garbage IMO. They don't test at the tailpipe in NH, only OBDII plug in so people do run catless Subarus around here because you can easily tune them out of the ECU so they never throw a check engine light, but I hate the way it sounds. 3 cats is ******* ridiculous though, I wouldn't be able to sleep at night knowing there were so many on anything I owned lol. My CJ is catless, my 280zx is catless, most vehicles I have owned over the years have been catless. Yuck I hate them
 

gotyourgoat

Full Access Member
Joined
Mar 27, 2014
Posts
2,117
Reaction score
3,417
Location
NRV Virginia
First Name
gotyourgoat
Truck Year
1984
Truck Model
c10
Engine Size
smokin' 305
Poll updated for factory non cat trucks and multiple responses for multiple trucks.
Ive got a big ten... factory non cat (or other emissions). Headers and true duals.

You must be registered for see images attach

When i was looking for a c10 one of the must haves was a non cat truck. The heavy 10's from 75-78 and non kalifornia 79's didn't have cats.

Factory fresh without them. 38 years later, still not required even in this communist-libtard state of CA. 1981 3/4 ton.

My 78 k10 is a factory non cat truck. Factory duals as well. Still running duals with no cats.
 

gotyourgoat

Full Access Member
Joined
Mar 27, 2014
Posts
2,117
Reaction score
3,417
Location
NRV Virginia
First Name
gotyourgoat
Truck Year
1984
Truck Model
c10
Engine Size
smokin' 305
No, just cutouts instead.

You must be registered for see images attach
Nice. Are those adjustable on how much they open or are they either open/closed? Say you wanted just a little open for half rowdy instead of full on rowdy.
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
28,956
Reaction score
23,466
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
I'm a solid 'No' with a mixed bag of reasons. Of all my trucks, only two of them were sold new with a catalytic converter. One of them is my '88 Burb, I removed that one when when I installed headers and duals. It was a restrictive pellet converter anyway. The other is my '84 shortbed, that one was removed by the previous owner. I'm not necessarily opposed to putting cats on any of them. But only one gets driven very often, the others really aren't lowering the air quality around here so it would be money spent with minimal benefit. So I guess you could say I'm too cheap to install new cats.
 

Shorty81

Baby Boomer
Joined
Mar 19, 2018
Posts
2,850
Reaction score
5,056
Location
North West ohio
First Name
Darren
Truck Year
86
Truck Model
K20
Engine Size
496
Nice. Are those adjustable on how much they open or are they either open/closed? Say you wanted just a little open for half rowdy instead of full on rowdy.
These cutouts are full open or closed. There are others that operate from a remote and are fully adjustable in any position. But since I have a history of losing remotes......sigh. lol
 

Shorty81

Baby Boomer
Joined
Mar 19, 2018
Posts
2,850
Reaction score
5,056
Location
North West ohio
First Name
Darren
Truck Year
86
Truck Model
K20
Engine Size
496
Nice. Are those adjustable on how much they open or are they either open/closed? Say you wanted just a little open for half rowdy instead of full on rowdy.
I was hoping that this BB with headers and 3" pipes would sound really good with cutouts. But in reality it sounds ANGRY. It sounds like a old Kingswood wagon at the demo derby with the exhaust manifolds running through the hood !!
 

eskimomann209

Full Access Member
Joined
Jan 9, 2019
Posts
1,849
Reaction score
1,998
Location
Modesto
First Name
Marcus
Truck Year
1973
Truck Model
C10
Engine Size
5.3
No cats true duals with old school cherry bombs. 1973 originally 454.
I’ll be doing cutouts someday too.
 

Craig 85

Full Access Member
Joined
Jan 25, 2017
Posts
3,889
Reaction score
4,024
Location
Nashville, TN
First Name
Craig
Truck Year
1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
This is one of the reasons I got rid of my '79 K15. I wanted a catless truck with the bonus of a 454.
 

Backfoot100

Full Access Member
Joined
Aug 18, 2017
Posts
374
Reaction score
643
Location
Florida
First Name
Eddie
Truck Year
1986
Truck Model
C1500 Suburban
Engine Size
Carbed 350
I have an '86 350 Sub that I bought pretty much stock. I put headers and true 2.5" duals with turbo mufflers and got rid of the cat at that time.
That new exhaust along with a quality tune up and carb rebuild really woke it up. It'll at least get out of it's own way now.
 

Goldie Driver

Full Access Member
Joined
Mar 19, 2018
Posts
3,924
Reaction score
6,375
Location
Houston, Texas
First Name
Britt
Truck Year
1980
Truck Model
GMC K1500 Suburban
Engine Size
350
No cat on Goldie - somewhere in life before me it got removed.

No factory air pump, either, even though the emmission decal shows it.

The rest of the junk is there, though- not having a functioning EGR valve caused HORRIBLE clatter for a while on the highway until I read up and tested the old, and fixed it and the EFE.

In the past, when exhaust shops weren't skeered to pull them , OFF with the bastages !:D

I will say 1 advantage to a single exhaust ( with or without cat) is they don't seem to rot out as fast since they run hot enough to burn the moisture out.

My experience, anyway.
 

1987 GMC Jimmy

Automobile Hoarder
Joined
Jan 23, 2016
Posts
5,848
Reaction score
2,387
Location
Mississippi
First Name
Jesse
Truck Year
1987
Truck Model
V1500 Jimmy
Engine Size
350
No cat on Goldie - somewhere in life before me it got removed.

No factory air pump, either, even though the emmission decal shows it.

The rest of the junk is there, though- not having a functioning EGR valve caused HORRIBLE clatter for a while on the highway until I read up and tested the old, and fixed it and the EFE.

In the past, when exhaust shops weren't skeered to pull them , OFF with the bastages !:D

I will say 1 advantage to a single exhaust ( with or without cat) is they don't seem to rot out as fast since they run hot enough to burn the moisture out.

My experience, anyway.

You might be onto something. 35 year old single exhaust looks brand new, the dirt notwithstanding, on the car, but the true duals on the truck not so much. I would like to see duals that old on a vehicle that’s driven at least three days a week.

Also, I really don’t think these little cars and trucks do that much even without the emissions stuff. The United States is like 10% of the world emissions, right, so once almost everyone switches to their little soy lattes on wheels, I’m willing to bet emissions from the vehicles we were smart enough to keep are pretty negligible when you stack it alongside everything else.
 

SirRobyn0

Full Access Member
Joined
Dec 6, 2019
Posts
6,698
Reaction score
11,150
Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
No emissions testing on vehicles that old in my state, and as far as I know any other state I have ever been to doesn't care either as my truck isn't registered in their state (and to the best of my knowledge most states have similar age based exemptions anyway).
For anyone wondering about this there are states that test back into the 70s. In the areas of Oregon that emission testing is done they do it on all vehicles 1976 and newer, no I'm not making that up.
 

SirRobyn0

Full Access Member
Joined
Dec 6, 2019
Posts
6,698
Reaction score
11,150
Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
I will say 1 advantage to a single exhaust ( with or without cat) is they don't seem to rot out as fast since they run hot enough to burn the moisture out.

My experience, anyway.

You might be onto something. 35 year old single exhaust looks brand new, the dirt notwithstanding, on the car, but the true duals on the truck not so much. I would like to see duals that old on a vehicle that’s driven at least three days a week.

Also, I really don’t think these little cars and trucks do that much even without the emissions stuff. The United States is like 10% of the world emissions, right, so once almost everyone switches to their little soy lattes on wheels, I’m willing to bet emissions from the vehicles we were smart enough to keep are pretty negligible when you stack it alongside everything else.

Because cats clean up the exhaust, they will help increase exhaust system life. Also getting them up temperature, and on a single exhaust system there is more overall volume of air coming out helping to push moisture and contaminates out. I think this is one of the reasons no new vehicle (with maybe a rare exception), has come out in a long time with true duel exhausts, instead you might get single 3" or bigger pipe. It's not uncommon for a V-8 exhaust to come together in Y-pipe, go through the cat, muffler and then split and come out looking like duels. It also eliminates balance issues associated with a true dual system. This is a real blast to fight by the way, I've had vehicles come in the shop with symptoms similar to having a heat riser stuck closed or partway closed only to find out there is a back pressure difference side to side in the duel exhaust. Simple solve is add a cross over pipe if the difference isn't to extreme.

When you think about the fewer number of older vehicles on the road I doubt if every single square owner cut off his cat that it would amount to anything measurable globally, especially when you consider industrial pollution. But if you live in a city, in particular a city with serious smog issues, like LA, and LA use to be much worse off than they are today reducing the emissions of cars is one of the things that has helped them out.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,008
Reaction score
8,973
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Federal Non Cali 86 C20 Big Block truck did NOT come with them. Does not have unleaded filler pipes on the tanks, and does NOT have Unleaded Fuel Only on the Gas Gauge.
 

Tiny dime

Junior Member
Joined
Oct 25, 2018
Posts
7
Reaction score
3
Location
Smyth county
First Name
Jonah
Truck Year
1986
Truck Model
K10
Engine Size
350
My 86 k10 had all smog emissions deleted. When I bought the truck all that was left was the catalytic converter. When my muffler rusted off I had to fix it a hammer a piece of pipe :ehcapt: So its still there but gutted. Just in case the inspection man looks to see about it.
 

Latest posts

Forum statistics

Threads
41,849
Posts
903,441
Members
33,362
Latest member
Dhatch84
Top