Remove catalytic converters? (1 Viewer)

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Apr 12, 2019
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Farmington NM
Hey all, tried the search option but nothing seems to pop up for remove catalytic converters. I have my 95 LC DD for around town and out in the desert hills almost daily. Can take my dogs running and exploring. Anyways, we have no emissions testing where I live and have thought about removing the catalytic converters. Who else has done this? Has it helped with gas mileage? Power? I have a Borla muffler on now and don’t want anything loud. Also don’t want any engine codes thrown if I do this. Experiences? Thoughts? Pros? Cons? Tia!
 
Joined
Nov 9, 2012
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Location
Olathe, KS, USA
Hey all, tried the search option but nothing seems to pop up for remove catalytic converters. I have my 95 LC DD for around town and out in the desert hills almost daily. Can take my dogs running and exploring. Anyways, we have no emissions testing where I live and have thought about removing the catalytic converters. Who else has done this? Has it helped with gas mileage? Power? I have a Borla muffler on now and don’t want anything loud. Also don’t want any engine codes thrown if I do this. Experiences? Thoughts? Pros? Cons? Tia!
Go park it in Seattle for a bit. They'll take care of it for you.
 

Dissent

Questioning my life choices...
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I'm considering doing the same, I'm in a county in TN now where emissions aren't required. Benefits would be better clearance, less restrictive exhaust (assuming partially plugged 20+ year old cats) and it lessens the appeals for sticky fingered losers in Seattle and other cities. You may be able to see them to some poor soul who still lives in a emission constrained county. It shouldn't make a noticable difference in the the exhaust decibel level but will give a (probably not noticeable) boost to HP and mileage but will definitely make your rig breath better and be one less area of service when the cat internals let go and plug your exhaust. It will probably throw a code depending on your OBD version but would depend on the health of your O2 sensors too as they measure before and after the cats. Curious how it turns out!
 
Joined
Apr 12, 2019
Messages
94
Location
Farmington NM
I'm considering doing the same, I'm in a county in TN now where emissions aren't required. Benefits would be better clearance, less restrictive exhaust (assuming partially plugged 20+ year old cats) and it lessens the appeals for sticky fingered losers in Seattle and other cities. You may be able to see them to some poor soul who still lives in an emission constrained county. It shouldn't make a noticable difference in the the exhaust decibel level but will give a (probably not noticeable) boost to HP and mileage but will definitely make your rig breath better and be one less area of service when the cat internals let go and plug your exhaust. It will probably throw a code depending on your OBD version but would depend on the health of your O2 sensors too as they measure before and after the cats. Curious how it turns out!
I’m in NM and moving to TN next year. I’d like to get this done before making the 1500 mile move. 😁
 
Joined
Jan 8, 2012
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Kind of along the same lines of thought as @BILT4ME , keep those cats and sell them to a recycler, since you can prove it’s your vehicle. Supposedly LC’s have some pricey ones.
 
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MN, USA
I recently completed a pair delete, relocated my O2s to the exhaust manifold and had a brand new OEM exhaust system installed from the headers to the tailpipe. However, I used a cheap aftermarket muffler (BRExhaust) & had straight pipes fabbed up for cats. I haven't been tracking mileage before or after, so I can't really speak to that. I do have more power, but that may be due to finally having an exhaust system that isn't swiss cheese. No CEL codes.
 

baldilocks

Battle Ground, WA
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Leave the cats. They are the first thing between your engine and stench. If they are plugged it’s not their fault.
 

Broski

I love Wheelin my 80
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Morro Bay, At the edge of the Pacific ocean
BAD IDEA
The car was designed to run with them there will be no performance or mileage gains and it well be throwing codes.
Like others have said it well smell really bad
 

cbmontgo

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Divide, Colorado
One of my 80s has the cats removed (I inherited it that way and we don't have emissions testing here). Exhaust smells pretty bad and I don't notice any performance difference between this 80 and my other one which has both cats. Both are 1996 models.

Your CEL will always be on, and it doesn't improve fuel economy either.

I'd leave it alone if everything is working.
 
Joined
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Olathe, KS, USA
One of my 80s has the cats removed (I inherited it that way and we don't have emissions testing here). Exhaust smells pretty bad and I don't notice any performance difference between this 80 and my other one which has both cats. Both are 1996 models.

Your CEL will always be on, and it doesn't improve fuel economy either.

I'd leave it alone if everything is working.
If the CEL is always on and the exhaust smells bad, you're overfueling all the time.

This is why they install the diode or whatever in the O2 sensor harness to fool the ECU into thinking everything is normal. This will improve the gas mileage a bit and should help some with the fuel smell exhaust.
 
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If you like throwing codes, running rich and smelling like a janky old lawnmower, that's your prerogative.

I personally wouldn't do anything to deliberately worsen the air quality where I live, and I hope most of my neighbors feel the same way.
 

cbmontgo

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If the CEL is always on and the exhaust smells bad, you're overfueling all the time.

This is why they install the diode or whatever in the O2 sensor harness to fool the ECU into thinking everything is normal. This will improve the gas mileage a bit and should help some with the fuel smell exhaust.
I may have to look into this. This is a mod that can be done?
 
Joined
Jan 19, 2005
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Location
South west utah
Don't remove them. Unless you like check engine lights.


These aren't chevy v8's from the 1980's. Doing a straight pipe exhaust won't create any improvement. Unless you also open up the air intake and or run forced induction.

It won't even sound cool.
 

Dissent

Questioning my life choices...
Joined
Sep 27, 2012
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Sweetwater, TN (East of Knoxville)
I recently completed a pair delete, relocated my O2s to the exhaust manifold and had a brand new OEM exhaust system installed from the headers to the tailpipe. However, I used a cheap aftermarket muffler (BRExhaust) & had straight pipes fabbed up for cats. I haven't been tracking mileage before or after, so I can't really speak to that. I do have more power, but that may be due to finally having an exhaust system that isn't swiss cheese. No CEL codes.
What year is your truck?
 
Joined
Nov 9, 2012
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Location
Olathe, KS, USA
I may have to look into this. This is a mod that can be done?
It is. I think it's part of the EGR delete.

I have no intent to do it, so I haven't followed it too closely, but maybe you can search EGR delete and get there that way.
 

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