Author Topic: Need Help With Exhaust in CA (done now with pics!) (Read 6042 times)

jb1981 · « **on:** May 13, 2007, 10:04:10 PM »

I'm trying to overhaul my exhaust on my 1981 pickup, which has to pass CA smog. Does anyone have suggestions on a header, muffler, catalytic converter, or anything exhaust related in general? Especially on the cat, for it to be smog legal, does it need anything specific (thermo sensor, air tube, etc.)? I'm pretty sure I'm going with a Thorley Header and 2.25" tube all the way back, but if anyone has any answers or suggestions, it would be greatly appreciated.

Thanks Everyone!
Jon in Elk Grove, CA

Duffil · « **Reply #1 on:** May 13, 2007, 10:45:49 PM »

go to an exhaust shop and get a universal cat. All it needs to be is there and in good shape. You can get a catco for like 100 or so installed around here. I run a Thorley, catco hiflow cat, 2.25 all the way back and a 2chamber flowmaster. The only thing bad I can say is they really don't like an overly rich condition, so if your carb dumps massive amounts of fuel, you won't get more than a month out of the cat. I blew mine out in about 3 weeks, but it smogged just fine.

AaronB · « **Reply #2 on:** May 14, 2007, 02:00:01 AM »

doesnt the cat need to be oem. i know mine has the air tube that goes in it.

Duffil · « **Reply #3 on:** May 14, 2007, 07:22:56 AM »

nope. the universal ones have a tube that is capped, if you need to hook it up, it's right there. It isn't until you get into OBDII that you can run into problems.

jb1981 · « **Reply #4 on:** May 14, 2007, 08:15:21 AM »

Aaron, what does your air tube connect to? So I don't need an OBDII cat, just OBDI?

All_Set · « **Reply #5 on:** May 14, 2007, 01:21:21 PM »

Quote from: jb1981 on May 14, 2007, 08:15:21 AM

Aaron, what does your air tube connect to? So I don't need an OBDII cat, just OBDI?

My cat has a tube but it remainded capped (from the muffler store i bought it from) as my '83 has nothing connecting to the cat. It passed smog fine. (everything stock)

BigMike · « **Reply #6 on:** May 14, 2007, 01:33:14 PM »

You only need OBDII cat(s) on vehicles that comply to OBDII standards, which, in America, are 1995+, however some new vehicles are now of a new onboard system, so I've heard.

madhunt · « **Reply #7 on:** May 14, 2007, 01:37:50 PM »

Quote from: Duffil on May 13, 2007, 10:45:49 PM

go to an exhaust shop and get a universal cat. All it needs to be is there and in good shape. You can get a catco for like 100 or so installed around here. I run a Thorley, catco hiflow cat, 2.25 all the way back and a 2chamber flowmaster. The only thing bad I can say is they really don't like an overly rich condition, so if your carb dumps massive amounts of fuel, you won't get more than a month out of the cat. I blew mine out in about 3 weeks, but it smogged just fine.

should of put flanges on your cat so you can take on and off, you only run a cat for the smog and then run stright the rest of time. thats what i did.

DTB · « **Reply #8 on:** May 14, 2007, 01:46:03 PM »

Quote from: madhunt on May 14, 2007, 01:37:50 PM

should of put flanges on your cat so you can take on and off, you only run a cat for the smog and then run stright the rest of time. thats what i did.

u could leave the cat on too...breathing clean air is nice..take it from a hippie

Duffil · « **Reply #9 on:** May 14, 2007, 02:05:27 PM »

Quote from: madhunt on May 14, 2007, 01:37:50 PM

should of put flanges on your cat so you can take on and off, you only run a cat for the smog and then run stright the rest of time. thats what i did.

Nope, I won't do that. I don't like the sound when the cat is blown out/gone. I don't need that much rice. Not to mention it kills low end due to no backpressure.

Duffil · « **Reply #10 on:** May 14, 2007, 02:08:28 PM »

Quote from: jb1981 on May 14, 2007, 08:15:21 AM

Aaron, what does your air tube connect to? So I don't need an OBDII cat, just OBDI?

I didn't mean to confuse you here. You just need a cat. I only stated OBDII because that is when you start having issues with universal cats. Please refer to my first post.

jb1981 · « **Reply #11 on:** May 14, 2007, 03:00:32 PM »

Thanks for all the help everyone! What do you guys think about mufflers? I was thinking of just running a glasspack to maximize flow (and they're cheap and easy), but I don't want it to sound terrible either. Any ideas on mufflers that aren't too expensive?

DTB · « **Reply #12 on:** May 14, 2007, 03:11:24 PM »

Quote from: jb1981 on May 14, 2007, 03:00:32 PM

Thanks for all the help everyone! What do you guys think about mufflers? I was thinking of just running a glasspack to maximize flow (and they're cheap and easy), but I don't want it to sound terrible either. Any ideas on mufflers that aren't too expensive?

check ebay...there are some uber-cheap sites that have nice stuff...i got a flowmaster hushpower (new) for hella cheap (which i think is nice but have no idea because my

is still sitting in the garage)

Rocksurfer · « **Reply #13 on:** May 15, 2007, 08:34:42 AM »

Hippie #2 says leave the cat on too. Like some of the others have said if you don't know what you're doing just take it to a muffler shop. I had to replace a CAT once and it only cost 175.00 installed. Just make sure they don't just weld it in and remove the flanges. The capabilities to unbolt the muffler comes in handy when you twist it up on the trail.

TurtleTappers91 · « **Reply #14 on:** May 16, 2007, 09:25:58 PM »

Quote from: DirToyBoy on May 14, 2007, 03:11:24 PM

check ebay...there are some uber-cheap sites that have nice stuff...i got a flowmaster hushpower (new) for hella cheap (which i think is nice but have no idea because my is still sitting in the garage)

I have the hushpower on my 22re 'yota and love it. I still think its the best one for the application after running it over a year. Its stainless steel, sounds great, its small, comes in 2 inch in/out, and it does not get hot, you can touch it at any time.

.. I sound like a flowmaster salesman....

But I paid about $120. Too pricey for a muffler? I havn't had it long enough to find that one out yet.....

jb1981 · « **Reply #15 on:** May 17, 2007, 02:07:01 PM »

does anyone know if the thorley headers from summit come with a carb sticker?

Duffil · « **Reply #16 on:** May 17, 2007, 02:11:23 PM »

Nope. I didn't get one anyway. Smog guy never said a word, the O2 is up high.

AaronB · « **Reply #17 on:** May 17, 2007, 04:11:34 PM »

Quote from: jb1981 on May 17, 2007, 02:07:01 PM

does anyone know if the thorley headers from summit come with a carb sticker?

Mine didnt, also here is a pic of the cat i got from summit.

jb1981 · « **Reply #18 on:** May 17, 2007, 04:41:44 PM »

is that a thermo sensor welded to the cat? where do you hook that up?

Duffil · « **Reply #19 on:** May 17, 2007, 05:49:56 PM »

looks like an air tube to me.

8D3TOY · « **Reply #20 on:** May 17, 2007, 06:10:01 PM »

My 83 has the tube welded in the univ. cat I bought. The new cat solved 99% of my smog probs.

Wermz84 · « **Reply #21 on:** May 17, 2007, 06:54:36 PM »

I am more than happy with my LC Engineering header.

Bolted right in and fit very well, with an OEM exhaust gasket. Almost 2 years now and still no problems and the ceramic coating still looks new. except for the Mud

C.A.R.B. number welded on.

2 1/4" exhaust with Flowmaster muffler.

My buddy has a Thorley and it is very nice but he had some sealing issues and had to use some goopy stuff to seal it up. anybody else with a thorley have that? or was it just that one?

What ever you decide I hope you like it.

Duffil · « **Reply #22 on:** May 17, 2007, 07:41:17 PM »

Mine seals fine, as long as you use the Thorley gaskets. The upper emissions ports are slightly different than stock.

Wermz84 · « **Reply #23 on:** May 17, 2007, 07:50:18 PM »

Good to know. Thanks.

jb1981 · « **Reply #24 on:** May 17, 2007, 09:36:07 PM »

well thanks for all the help everyone! i just ordered all my stuff tonight; went with the thorley header, 2.25" tubing, universal catco, and a cherry bomb glasspack. should have it all on in about 2 weeks and i'll post pics.

jimbo74 · « **Reply #25 on:** May 17, 2007, 10:26:33 PM »

unlike all the peopel that run without a cat, i run with a cat, just no muffler, unless i need to have it inspected, then the muffler goes back on... my muffler has a welded sleeve on it, and a muffler clamp attached to the muffler, so its pretty much slide it on, hang the muffler up, and clamp it down.....

my cat has a port on the side for a probe, and my truck has a temp probe, but i have heard its fine to run without it.

muffler has a turndown

jb1981 · « **Reply #26 on:** Jun 08, 2007, 02:59:23 PM »

well i know i said i'd post pics of the exhaust so here they are.
i went with a thorley header, 2.25" tubing all the way back, a universal cat (with welded-on flanges), and a cherry bomb glasspack.
i'm thinking of painting the tubing blue to match the smog rail and the valve cover accents

from top to bottom:
the thorley header
the system from the front
the system from the rear
my "custom" air intake (just a larger filter, extended stem from the carb to bolt it down and an extended breather hose to the valve cover)

the intake and exhaust made a huge power and torque difference.

DTB · « **Reply #27 on:** Jun 08, 2007, 03:21:57 PM »

Quote from: Captain4x2 on May 17, 2007, 10:26:33 PM

unlike all the peopel that run without a cat, i run with a cat, just no muffler, unless i need to have it inspected, then the muffler goes back on... my muffler has a welded sleeve on it, and a muffler clamp attached to the muffler, so its pretty much slide it on, hang the muffler up, and clamp it down.....

my cat has a port on the side for a probe, and my truck has a temp probe, but i have heard its fine to run without it.

muffler has a turndown

how loud is that without a muffler? i might have to run mine with no muffler for a couple days and was just curious....

AaronB · « **Reply #28 on:** Jun 08, 2007, 04:09:00 PM »

Quote from: jb1981 on Jun 08, 2007, 02:59:23 PM

well i know i said i'd post pics of the exhaust so here they are.
i went with a thorley header, 2.25" tubing all the way back, a universal cat (with welded-on flanges), and a cherry bomb glasspack.
i'm thinking of painting the tubing blue to match the smog rail and the valve cover accents

from top to bottom:
the thorley header
the system from the front
the system from the rear
my "custom" air intake (just a larger filter, extended stem from the carb to bolt it down and an extended breather hose to the valve cover)

the intake and exhaust made a huge power and torque difference.

what did you have to do to get the smog rail on the header?

Wermz84 · « **Reply #29 on:** Jun 08, 2007, 05:23:00 PM »

Looking Very nice Jb1981

I am still super stoked on my header and exhaust.

Quote from: Aaronb on Jun 08, 2007, 04:09:00 PM

what did you have to do to get the smog rail on the header?

I think thorley has a couple of different options, I could be wrong though.

Quote from: DirToyBoy on Jun 08, 2007, 03:21:57 PM

how loud is that without a muffler? i might have to run mine with no muffler for a couple days and was just curious....

I had to drive mine on a open header a half an hour on the open highway to get to the muffler shop, LOUD!!

Although climing the hill between santa cruz and watsonville in fourth gear pinned was fun..

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