Removing catalytic converter

[Benji88]

My 13 silverado has 5.3 with longtube headers catless offroad y pipe but does have a cat like 12 to 14" from the y pipe and I want to remove the catalytic converter will my truck run good without it or will it need to be re tuned downstream oxygen sensors are deleted also

[Black02Silverado]

7 hours ago, Benji88 said:

My 13 silverado has 5.3 with longtube headers catless offroad y pipe but does have a cat like 12 to 14" from the y pipe and I want to remove the catalytic converter will my truck run good without it or will it need to be re tuned downstream oxygen sensors are deleted also

You would have to have a tune to turn off the O2's  past the CAT's.  If you do remove them, be prepared for a super stinky strong exhaust smell. If you park in a garage it will really fill it up.  When I had my 65 Impala and backed it into the garage, I could barely breath when I got out of it the smell was so strong since it didn't have CATs.

[Benji88]

1 hour ago, Black02Silverado said:

You would have to have a tune to turn off the O2's  past the CAT's.  If you do remove them, be prepared for a super stinky strong exhaust smell. If you park in a garage it will really fill it up.  When I had my 65 Impala and backed it into the garage, I could barely breath when I got out of it the smell was so strong since it didn't have CATs.

Well the oxygen sensors after the cat are allready deleted and the cat is not placed where its supposed to go its father back I think the truck wasnt running with cats I think the dealership or previous owner put it on.

[pronstar]

If you do remove them, be prepared for a super stinky strong exhaust smell. If you park in a garage it will really fill it up.  When I had my 65 Impala and backed it into the garage, I could barely breath when I got out of it the smell was so strong since it didn't have CATs.

True to a point...but a modern engine without cats is still miles cleaner than anything made in 1965.


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[Black02Silverado]

Just now, pronstar said:

 

True to a point...but a modern engine without cats is still miles cleaner than anything made in 1965.


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True, but I installed multi port fuel injection on it.  So I was hoping it would burn a little cleaner. 

[Benji88]

So that means there wouldnt be any problem removing the cat since the oxygen sensors after the cat are already deleted???

[Black02Silverado]

Just now, Benji88 said:

So that means there wouldnt be any problem removing the cat since the oxygen sensors after the cat are already deleted???

Correct.

[Benji88]

Ok cat is being removed next week thanks everybody for the help on removing catalytic converter.

[Colossus]

May I ask why you want to remove the cats?  Generally, there will not be any performance gains. 

[75z28]

9 hours ago, Black02Silverado said:

True, but I installed multi port fuel injection on it.  So I was hoping it would burn a little cleaner. 

heck it should! I went from carb(stinky) to a MPFI on my big block and it is MUCH cleaner all the way around.  The carb would idle at around 12.8:1(any leaner and it would die) where the MPFI will idle at 13.9:1 all day and doesn't really smell up the garage

[Benji88]

12 hours ago, Colossus said:

May I ask why you want to remove the cats?  Generally, there will not be any performance gains. 

Well my truck doesnt have have stock manifold it has longtube headers catless y pipe and the catalytic converter is placed further back the y pipe oh and its getting re-tuned afterwards

[swathdiver]

On 11/18/2018 at 11:15 PM, Colossus said:

May I ask why you want to remove the cats?  Generally, there will not be any performance gains. 

I've never known this to be true when I used to race.  

[Benji88]

I already know that but my truck already has a bit of hp gain has longtube headers offroad catless y/pipe cat was placed bit futher back already deleted it

Edited November 20, 2018 by Benji88