To Gut a cat or not to Gut a cat, that is the question

[dragracefan]

Has anyone who has removed the Catalytic converter noticed a difference in performance or not.

I am not worried about a check engine light code P0420, I know how to get around that.

 

[tidefan1967]

Unless the cat is plugged up there's little to gain by removing it. Now if we were talking about the cats they used in the 70's it would be a different story but modern cats are pretty decent.

 

[Tim S]

First off, I have the 8.0L v10. One of my catalytic converters was plugged and when I removed them, there was a definite, but expected increase in power. Alot. I just put catalytic converters back on for inspection and there was a loss of power, just barely enough to notice

 

[dragracefan]

Thanks, the one on my truck has 190k and it was a oil burner. I have this 414 c.i.d. stroker now and the thought crossed my mind, may squeeze a few more HP.

 

[Yeret]

Modern cats, especially good aftermarket ones, flow well and impede peak power quite little. Actually, the power difference between no cat and a clean one have been shown to be several at most. For several more horsepower, you also get an everlasting CEL and the vehicle becomes technically illegal in most states (whether or not emissions are actually ENFORCED is another matter).

Cats also make decent mufflers with the right exhaust setup. Me, I'm running a Magnaflow unit with no muffler and the truck is nice and loud but not ridiculously so. I mean, I've driven past many cops with this setup and they've never bothered me. Hell, the few trucks around here that still run twin straight pipes are a lot louder. So, basically, if you lop off the muffler and run a cat, you still yield improved exhaust flow without making things too loud AND you don't have to worry about the other crap that results from not having one.

 

[meistermash]

I don't live in a ****** state so no inspection.
My 01 no longer has a cat problem.
To get around the cel light I installed two spark plug non foulers in the rear o2sensor ****.
The Napa has those non foulers. One will have to be drilled out to clearance the end of sensor.
I will admit though, there is not much difference in pre plugged cat and post cat.
If yours is plugged though, there will be.
As far as loud junk goes, I like my stuff as quiet as can be had. So full mufflers and exhaust for my rides.
I would like to install a remote cut out for those times the neighbors crank up their 100 year out of date engine tech, scooter bikes.
Then I could get some payback for those crappy sounding "loud pipes saved lives" moments.