Delete cat, replace with muffler? (Page 1/2)
ltlfrari APR 07, 02:14 PM
So here's a thought.
I am going to pull my motor soon(ish) to swap the gearbox but while everything is out I was going to delete the cat because a) no emissions now and b) it smells of bad eggs so I suspect the cat is going out anyway (again) but I just had the thought to instead put a muffler where the cat goes and delete the muffler under the trunk, thus freeing up a ton of room plus the need to fight with those bloody springs and just have the tail pipes out the end.

Thoughts?

------------------
Anything I might say is probably worth what you paid for it, so treat it accordingly!

Dave

www.ltlfrari.com

Dennis LaGrua APR 07, 02:40 PM
I would not add another muffler there. You are ready have one so you will restrict the flow and lose power by adding a second muffler. You can purchase a new head pipe from the Fiero Store that allows replacing the CAT with a non-restrictive straight pipe. Your engine will run better, you will be removing a significant exhaust restriction, a dangerous fire hazard and preventing CAT theft. Of course for "off road use" only.
------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 04-10-2021).]

skywurz APR 07, 02:54 PM
When talking about this be aware of


quote
Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles. Anyone who installs such pipes would violate section 203(a)(3)(A) and (B) of the Clean Air Act (Act).



Its a $2750 fine.

ltlfrari APR 07, 08:33 PM
I was actually thinking of removing the original muffler so it's just a straight pipe and putting 'the one and only muffler' where the cat is currently.
But at the risk of a pushing three grand fine, maybe I won't!

I've actually got the FS cat delete pipe but maybe I'll just live with the bad eggs smell.

[This message has been edited by ltlfrari (edited 04-07-2021).]

Spoon APR 07, 08:37 PM

quote
Originally posted by skywurz:

When talking about this be aware of


Its a $2750 fine.



Does the law specify any exceptions for off-road vehicles or is that a gray area?

Spoon

------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

Xenoblast APR 07, 09:54 PM

quote
Originally posted by ltlfrari:

But at the risk of a pushing three grand fine, maybe I won't!




Dont worry about that fine if your state has no emissions laws. Thats like the feds coming after you for being in possession of marijuana in a state that allows it. its not gonna happen.

My state has no emission, but I replaced it with a flowmaster cat anyway bc i heard that fieros sound bad without it. Also i dont want my car to smell
OH10fiero APR 08, 02:28 AM

quote
Originally posted by Xenoblast:


Dont worry about that fine if your state has no emissions laws. Thats like the feds coming after you for being in possession of marijuana in a state that allows it. its not gonna happen.

My state has no emission, but I replaced it with a flowmaster cat anyway bc i heard that fieros sound bad without it. Also i dont want my car to smell



Any shop that works on a car can also turn you in if they see the converter was removed, not all of them will turn you in but they are supposed to so keep that in mind.
ltlfrari APR 08, 07:27 AM

quote
Originally posted by OH10fiero:


Any shop that works on a car can also turn you in if they see the converter was removed, not all of them will turn you in but they are supposed to so keep that in mind.



Well, no inspections here for my car now (over 25 years old) and only I work on it so probably not an issue for me but I think I'l do the 'right' thing and keep the cat. It's not like a drive the car a lot anyway.
skywurz APR 08, 01:06 PM
My point was more of, probably best not to talk about violating federal law on a public forum if i were you i would have prefaced it with "for off highway use" or "for track use" idk i spend some good time on motorcycle forums where CAT delete are more common conversation but just as illegal.
Blacktree APR 08, 01:36 PM
Here's something to keep in mind: the catalytic converter is strategically placed where it can warm up fairly quickly (so it can do its job). Mufflers are usually placed near the end of the exhaust, where the exhaust gases are cooler. Putting a muffler where the catalyst usually goes may shorten its life, due to the higher temperatures there.