Replace or delete Catalytic converters

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O2batsea

Well-known member
It's time to do something At present the RH side catalytic converter is making all kinda noises and I'm getting really poor mileage. Dunno if the two are related but I'm thinking of having the cats deleted. Is that a bad idea? Doesn't need to pass emissions any more.
 
Napalm00

Napalm00

Technical Excellence Contributor
putting a aftermarket 49 state cat is prob $50 ...the pipe is maybe $10

if you have obd2 or some obd1 vehicles you may get a warning light if the cat is missing. will run the same


Poor mileage is either the cats or the sensors , or many other issues
 
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O2batsea

Well-known member
I'm gonna see how much the Mexican guy charges to delete the cats. If it's less than a new y pipe, imma do it

No Matt this is on the 94 Loob. No fancy OBD stuff. Codes displayed on a HIDDEN device that requires that you take the sill plate and half the passenger seat base apart. Smart.
 
Uncle Douglas

Uncle Douglas

Well-known member
Callsign: delete
O2 sensors are before the cat on a loob. Mine has a y pipe Dr Bang opened up the cats on, removed guts and welded can closed again. Quick look underneath and they are there, but she breathes deeply and freely now.
 
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EricTheRed

Member
Since my 93 RRC here in Texas is only Safety only, I now don't worry about having no Cats. Mine was deleted about 7 years ago. I just put a 2.5 inch pipe with Flowmaster from the y pipe back. Sounds good too. With 4.11 gears and bumpers, lift, tire and fuel tank she actually still gets about 13.5 mpg. I am pretty surprised. If you can legally delete, just do it. The only drawback is the rich exhaust smell. It does get annoying at times.
 
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O2batsea

Well-known member
I can’t remember which one it was but one of my LWB got around 16 mpg. This current one, nope
It’s now exempt from smog testing in Maryland so I will probably delete them
 
ionfender

ionfender

Well-known member
erover82 said:
Did you route the tip straight out the back, or out the side?
Click to expand...
The first NAS 90 (soft top) I bought had the exhaust tip pointing straight out the back behind the driver side rear wheel...also had the cats deleted.

Every time I drove that thing I smelled like exhaust...real strong. Kind of annoying to be honest.
 
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erover82

erover82

Well-known member
1. As mentioned, removing the CATs will increase emissions (odor).

2. Routing your exhaust pipe anywhere but out the side, will cause the exhaust to recirculate in the vehicle's wake and unless sealed-tight, into the cab.

3. Don't do both 1 & 2.
 
ionfender

ionfender

Well-known member
erover82 said:
1. As mentioned, removing the CATs will increase emissions (odor).

2. Routing your exhaust pipe anywhere but out the side, will cause the exhaust to recirculate in the vehicle's wake and unless sealed-tight, into the cab.

3. Don't do both 1 & 2.
Click to expand...
Hahaha, I had both when I got the truck. Not good.
 
rover4x4

rover4x4

Well-known member
My RRC smells really bad, its got other underlying issues that are beyond my capabilities to address
LWB doesnt have catalytic converters and is really not that bad for whatever reason.

I am not sure if this "tune resistor" I've read so much about over the years would actually help.
 
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