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Remove the Catalytic Converter?

13K views 19 replies 10 participants last post by  Caddyshack100 
#1 ·
Alright, My cat Is makin some raddling noise and I was curious to see if I can remove it. I honestly believe I can't But I wanna here from you guys if I can or can't. I know I have a positive feed-back EGR system that Relies On Backpressure! But I didn't know if anyone has done it before and has some good or bad results!? I appreciate this ahead of time everybody. Thanks!
 
#2 ·
You can do whatever you want, however, removing a cat without putting a new one on is a FEDERAL OFFENSE. I have gutted a cat on my car because these cars are no longer emissions tested in Illinois, but if you live in a state where emissions are tested, you can get in some trouble for not having one.

You gain about 5hp from removing one, a little bit better fuel economy and a more aggressive exhaust note, but other then that nothing really changed.
 
#3 ·
With your 4.9L Does it have the same EGR system as mine? I live in florida, we did just sign over to the New California Emission. Except its for only those 2006 and up that have to meet those standards. Mine is "Grandfathered In". I am just afraid to remove the cat Or Gut it if its going to hurt the action of my EGR?
 
#4 ·
If your car has to be emissions tested in any way, it will fail without a cat converter. Removing the cat hasn't noticeably effected my EGR, and our engines should be nearly identical, but the pipes on a '94 Deville were straighter, and therefore make less back-pressure then mine do, so your effects may be different. The only way to find out for sure is to try though.

Here's the difference between my exhaust and your's:

'91-'93:

'94-'95:
 
#9 ·
Yeah, there arent any testing requirements in florida. The only thing they require is that everything 06 and Newer has to meet the requirements of its emissions. During standard servicing they will be looking. It hasn't started yet though. . . .
 
#10 ·
Alright, another question. . . Still about the exhaust system. Has anyone put a muffler on their cadillac yet? I am curious if I can and If it will sound good? My intensions are to put on a Flowmaster 40 Series or borla or even a magna Flow. Any ideas?
 
#12 ·
I used to do that on my performance cars. That was before I cared about the enviornment. Even though we don't have emissions testing it is still wrong. You wont gain any real performance other then the approx. 5hp, so why do it? If you want the 5 hp, at least put on a high performance cat and a cat back system, and feel good that you are not hurting the enviornment!
 
#16 ·
Why not just buy a hi-flow cat from any number of places, stay legal and get the extra 5 HP if you really need it.
 
#17 ·
Now, The same question pops up... I have been told so many times and With me knowing how the EGR works... I am worried that If I put a High Flow cat on it as well as a Performance Muffler... Something will happen with my egr and More problems will occur. Whats your opinion?
 
#18 ·
Of course you can, but don't expect the vehicle to run right unless you plan on doing some major PCM retuning.

In the 1970s you could get away with bypassing most emissions controls, because they were essentially just tacked on, but now emissions systems are so tightly integrated with engine control systems - and engine design itself - that removing them often causes more problems.

As much as I hate all this enviornment BS, I would replace the cat - with a genuine GM part.

Joe
 
#19 ·
According to "RODYA234", since a volcano can produce emissions if it erupts, then we don't need to worry about things like making our cars run cleaner. I don't know how to stop a volcano from erupting, but I do know how to leave emissions equipment on a car, and other painless ways to help clean up the enviornment.
 
#20 ·
These cars were meant to run with a certain amount of backpressure, the muffler as well as the cat work in tandem to acheive this, it is not a good idea for that reason alone to remove the cat. The big carmakers, Domestic and Foreign have had a spotty record when it comes to having emission controls work properly (anybody remember the infamous Chrysler "Lean Burn" system? How many people ripped that out of their cars as soon as possible. As for volcanoes, I did not myself think anything of them until about 10 years ago when it was discovered that Mount Pinatoubo during one eruption emmitted more CFC and CO2 into the atmostsphere than Mankind has done with all the CFC in our cars and cans in our history. Let see if Al Gore can explain that inconvienent truth. Its the same as the Green crowd wants North America to do all it can to negatively change our way of life while China and India happiliy bypass and reap the reward of our stupidity and at our expense.
 
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