Gutting Catalytic Converters

[firedawg]

Has anyone seen a list of directions anywhere for gutting catalytic converters or could anyone give me their own? I was just wanting to find the easiest way to do this. Is there a way to do this without cutting them open? Any help would be greatly appreciated. THANKS

 

[rrubel]

Mad Mic and I played with gutting a cat; essentially he took a long crowbar and punched chunks out of the catalyst honeycomb, then shook the pieces out into a trashbag. Took maybe half an hour, I think.
[RICHR]

 

[1995 RedVette]

I saw the same thing being done to an 87. The car was daily driven and the owner complained of it being slugish etc and requested that the cat be taken out. The mechanic offered to remove the insides of the cat rather than remove it and fab a new pipe and flanges. He accomplished this by the use of the large crowbar and hammer.

Brett

 

[firedawg]

I'll have to try the crowbar/hammer method, I want free flowing exhaust, but am still a little nervous about MD emissions testing, I haven't had to have it done yet on my vette so I haven't been able to try the "height waiver" trick I've heard about. I figured if it at least looked like I had cat's on there if they don't test it, they may pass me because it looks like everything's in place.

Another thing, does anyone know where to buy the things that make your computer think there's a properly working o2 sensor right behind the cats? I know I've seen them somewhere, but can't find them now for some reason.

 

[Mad-Mic]

you shouldn't need O2 sensors things ( can't think of the proper name right now ) with your new plugs and a good tune you can still pass MD emissions testing with a few tricks. run it hot going in. add a bottle of rubbing alcohol to the fuel tank with a 1/4 tank of fuel and hope for the best only thing that will be high is hydro carbons but you can still get it thru.

i'm running mine thru next week and i'll let you know what happens.

I'll have to try the crowbar/hammer method, I want free flowing exhaust, but am still a little nervous about MD emissions testing, I haven't had to have it done yet on my vette so I haven't been able to try the "height waiver" trick I've heard about. I figured if it at least looked like I had cat's on there if they don't test it, they may pass me because it looks like everything's in place.

Another thing, does anyone know where to buy the things that make your computer think there's a properly working o2 sensor right behind the cats? I know I've seen them somewhere, but can't find them now for some reason.

 

[firedawg]

without the o2 "thing" :L will my check engine light come/stay on?


Let me know how you do! I have been holding off for a while because of that! :eyerole

 

[Mad-Mic]

without the o2 "thing" :L will my check engine light come/stay on?


Let me know how you do! I have been holding off for a while because of that! :eyerole

no your light shouldn't come on. i run regular o2 sensors in mine and have no problems.

 

[ShaneL]

I got a set of pipes that just go in place of the CATs, but because I have a 1996 model which = OBDII, I have an oxygen sensor before the Cats and after the CATs. The "thing' that you are referring to is an O2 SIM. Just for reference, you can get them from TPIS but I beleive that they are going to remove them from the online store due to mix-ups between people ordering the square style connector and needing the flat style or vice-versa.

-Shane

 

[-=Jeff=-]

without the o2 "thing" :L will my check engine light come/stay on?


Let me know how you do! I have been holding off for a while because of that! :eyerole

you are thinking of O2 Simulators. your 93 has 1 maybe 2 O2 sensors, the Simulators go after the cats, found on OBDII cars and will not be on yours

 

[Vettelt193]

yeah... 1993 was the last year of the 'quick and easy' cat removal. no extra sensors necessary

 

[firedawg]

So will I need to do anything else with gutting the cats? I have no other mods except borla exhaust. any computer recalibration or anything?

 

[Mad-Mic]

So will I need to do anything else with gutting the cats? I have no other mods except borla exhaust. any computer recalibration or anything?

no you should be fine i don't think it will throw a code. i know you have the LT1 and i got the L98 motor but i didn't throw any codes afterwards either.

 

[firedawg]

Cool, I just wanted to check, a guy at work was saying all this stuff about how it would mess up the computer and everything, I didn't really listen to much he had to say, especially after he said he did it to a truck of his (not sure what kind of truck) and didn't say anything of any trouble he had. I just wanted to make sure from some people who knew about 'vettes. Thanks again!

 

[spyysee]

no problem w emission testing...140,000 mi, passed ok

 

[sothpaw]

they do still test vettes...

... Fire,

I have a 1993 like yours and I just did the MD emissions in Glen Burnie a few weeks ago. 2 year ago, I got a waiver, but not this time.

Be sure to turn your traction control off. They're not bright enough to do that.

 

[firedawg]

Southpaw,
Do you still have the cats on your car? did you do anything else special to pass?

 

[WhalePirot]

run fast AND clean

You should know that intentionally doing this to your emissions equipment is a hefty fine from the Feds. I suggest reading at least the start of the Emissions Tampering thread, atop this list.

I cannot understand why you want to remove equipment that allows your ECM to properly control your engine (O2 sensor), either. Just because people do not understand how and why the parts are there does not make them suspect of hindering performance. If your CAT(s) is(are) plugged, replace it(them) after finding out the reason for the clogging.

I ran with a test pipe in place of a CAT for a very short time and found absolutely no difference in performance. I now run a new stock CAT with my 3" exhaust and the car is scary with performance. I also can sleep at night knowing that I don't have to fret getting nailed at any time, because someone smelled my non-CAT exhaust and I got caught. I am probably unusual in feeling comfortable with taking responsibility for keeping my car clean running, while having performance few can enjoy; hence, I'll put my Vette up against any other in here for excitement in driving.

I guess you guys can flame me for disliking what I consider to be contrary to responsible ownership and contrary to the interests of enthusiasts. Such folks invite lawmakers to clamp down further and ruin the hobby, as they have nearly totally succeeded doing in CA. In my experience, if there are any performance gains rom removing emissions gear, they are minimal and not worth the potential cost.

 

[Vettelt193]

not gonna flame you, that is the most responsible stand point... on the flip side though, you are a bit off on a couple of things.

First off, The older the car is the more performance gain you can get from removing the cats. I am very surprised that you did not see a difference in performance when you tried it out on your car.

Second, there are other reasons to remove the cat besides performance. interior heat is a big one... also, on LT1/4 cars one cat is right next to the oil filter... not good for oil temps, and makes life a real PITA when it comes to changing oil. (interior heat + the oil change thing are reasons why I would like to dump the cats on my car)

Also, the O2 sensors you talk about removing are for emissions purposes.

 

[WhalePirot]

the O2 sensors you talk about removing are for emissions purposes

Not entirely true..

The O2 sends feedback to the ECM to adjust mixture and to optimize fuel burn. Emissions is certainly related, but a properly adjusted engine, whether ECM controlled or properly tuned some other way, runs cleanly AND puts out the most power it can. Without sensor feedback, the car is running blind.

 

[Vettelt193]

I don't know what your car is like, but later C4's have O2 sensors before the cats, as well as after the cats. the ones after are for emissions, before cats are the ones you are thinking of.