OK to discard Cat Convertor
06-21-2017, 04:17 PM
#1
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Join Date: Dec 2016
Location: West Florida
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Year: 1998
Model: Grand Cherokee
Engine: I6 - 4.0
OK to discard Cat Convertor
1998 GC w/4.0 auto
The exhaust has a leak - which is weirdly; a radial ring of 1/4" holes. Maybe some spot welds broeke or pulled apart or something?
Anyway; I was thinking to wire brush and patch the holes but the pressure coming out of the little holes seems pretty darned 'high pressure' while the pressure coming out of the tail pipe seems pretty darn low-flow.
Which leads me towards the idea that maybe something in the exhaust system is plugged up? So rather than patch the holes maybe the muffler and pipe behind it would be better off replaced?
Question: will leaving the catalytic converter off cause any Harm to the vehicle?
There is no vehicle inspection in Florida so legality is not an issue.
Is there any operational benefit to having the Cat. Installed?
Or for that matter; any operational benefit to have it off the truck? <g>
The exhaust has a leak - which is weirdly; a radial ring of 1/4" holes. Maybe some spot welds broeke or pulled apart or something?
Anyway; I was thinking to wire brush and patch the holes but the pressure coming out of the little holes seems pretty darned 'high pressure' while the pressure coming out of the tail pipe seems pretty darn low-flow.
Which leads me towards the idea that maybe something in the exhaust system is plugged up? So rather than patch the holes maybe the muffler and pipe behind it would be better off replaced?
Question: will leaving the catalytic converter off cause any Harm to the vehicle?
There is no vehicle inspection in Florida so legality is not an issue.
Is there any operational benefit to having the Cat. Installed?
Or for that matter; any operational benefit to have it off the truck? <g>
06-22-2017, 07:35 AM
#2
CF Veteran
Federal law requires a cat converter. Just because more air 'leaks' from the front than the back would not mean much ..this is expected as the cat does have some resistance. I would just pop a $100 converter, fed compliant, on it. That way your obd2 monitors wont be throwing you a check engine all the time, for starters.
06-22-2017, 11:59 AM
#3
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Join Date: Jan 2012
Location: Ocean County, NJ
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Year: 1998
Model: Cherokee
Engine: 4.0L
I'm going to agree with 97grand. A 98 is going to be looking for catalytic converter efficiency so if you remove it you'll have a permanent CEL. Magnaflow makes replacement cats pretty cheap. This is the route I would go.
06-22-2017, 12:23 PM
#4
Old fart with a wrench
NAPA used to have a nice small one for the Chevy S10 4.0 that would fit nicely for $50. The previous owner probably drilled those holes because the cat is plugged.
06-22-2017, 06:15 PM
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Year: 2001
Model: Cherokee
Engine: 4.0L I6 HO
I ran straight piped 2.5" from the down pipe back, for a while and never had a CEL from it. Still kept the main cat of course. I'm not sure if the GC 4.0 has the same exhaust style as the XJ. Got a crap llad better gas mileage. Was awesome lol. But I digress. OP, go with a hi flow Cat and muffler. regardless of state Inspection. I've noticed that every jeep reacts different with exhaust setups, I guess maybe due to engine age and such.