Pre-Cats
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Bad is probably the wrong word. The front cat is to reduce NOx gases while the rear is for Hydrocarbons. Modern cats do both now.
If you replaced your middle cat with a new model, you'd still get both functions. (Assuming you need to accomplish both).
If you don't replace your main cat and omit the front cats, the car will still run fine.
If you replaced your middle cat with a new model, you'd still get both functions. (Assuming you need to accomplish both).
If you don't replace your main cat and omit the front cats, the car will still run fine.
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
1st Gear
Joined: Jun 2008
Posts: 1
Likes: 0
I removed all mine, replaced the front "Y" with one that is without cats, and replaced the main cat as well. There are no mufflers on this car and it has LT1 tips. The interior noise is a little stout and it is has a very aggressive sound when under full throttle........but it runs pretty good!
Drifting
Joined: Oct 2006
Posts: 1,934
Likes: 3
From: Citrus Heights California
Or you could replace your precats with 2 bullet cats like these http://www.pysales.com/iwwida.pvx?;i...0%201?comp=ppe
and replace your main cat with an X pipe.
and replace your main cat with an X pipe.
Thread Starter
Intermediate
Joined: Apr 2008
Posts: 37
Likes: 0
Let me tell my story... I got the car with 192,000 miles on it I drive it home from above Atl. ( thats about 3 hrs.) the car ran fine it was just loud. The guy had drilled holes in the pre-cats cause he said they were stopped up. That Monday I had the pre-cats cut off and a week after that I had SpinTech race mufflers put on. It ran fine for about 2 weeks then it started acting up really bad. White smoke and black smoke, and the car would have like a bad lope to it driving down the road ( like if you had a really big cam and was setting at a red light where the car would want to go but couldn't ). Now I have had the motor rebuilt and everything changed and now it is running like crap ! It still has that lope to it going down the road and it is dumping gas like crazy. The guy that redone the motor did not check the ohms on the injectors nor did he check the tps nor the map sensor. My dad tested it and it had a code of 460.We don't know what the fuel pressure is nor is the timing set right,I really need some help with this if anyone that know anything about vettes and that lives anywhere around Tifton Ga., Albany or Valdosta, Macon, Alt PLEASE SEND ME A PM.
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