I have a 1990 Corvette that blew the engine. So I picked up a 5.7 ls1 out of a 2001 Corvette for a good deal to replace it. The 2001 didn't have any exhaust manifolds or cats. I live in California and will probably have to have the right cat set up to pass smog. My problem is that I dont know if it needs just two cats or if they had the four cat set-up as in later years. Any help in finding out what the 2001 Corvettes had for a catalytic converter set-up would be much appreciated.

 

2001 ls1 or ls6 would have 4 cats, the small pup cats at the front, 2002 and up have a larger main cat eliminating the pup cats

 

Ok. thanks. So then I'm wondering if I went with the newer style 2002 cats and had only two, if it would pass the visual. I'm pretty sure it would pass the emissions test cuz' it only has 70,000 mi. on it. Just not sure about the visual. Guess it depends on the smog tech that's checking your ride.

 

Ive done several C5 LS1/LS6 exhaust system swaps/repairs/up-grades.

Early C5 LS1 cars "97-2000" did not have PUP CATS. They had TWO MAIN CATS only:

I cant speak of any CALI Specific emissions for those car as there may have been some specific requirements.

This is a LATE MODEL 2004 C5 LS1 mid pipe with PUP CATS and two main cats:




This is the bottom of my 02 ZO6. It gives you a great understanding of how that stock C5 Mid Pipe would fit under the car. GM made a specific spot for the OEM cats to nest in.








I owned an 85 Auto Coupe. C4s came with a SINGLE mid-pipe and ONE long CAT further back. Fitting the C5 Mid pipe onto a C4 probably wont work or work easily. You may be able to STAGGER in some aftermarket high flow cats like the ones I used on my C5 aftermarket system. You may have to make a 2 into 1 Y pipe and keep your single exhaust system.

The LS engine uses TWO 02 Sensors as your C4 only uses ONE. The new C5 LS PCM needs to have as close to the OEM 02 sensor location as possible to work efficiency.

C5 had SEVERAL "EXHAUST SYSTEM " designs. They ALL look VERY SIMULAR BUT, some mid pipes wont fit other year C5s. The exhaust manifolds came in several different designs and that's what drives the different models of midpipes. It kind of goes like this:

97-99 LS1 are the same, 2000 LS1 is different, 2001-2004 LS1 are the same, 2001 ZO6 is unique as it is the only ZO6 that has PUP CATs. 2002-2004 ZO6 different.

If you GOOGLE "C5 Exhaust systems" and look at the IMAGES, you get TONS of pictures of all the different sets up people have taken pictures of:

https://www.google.com/search?q=c5+e...iw=998&bih=580

Compare that to your C4 exhaust pictures and that might help you get a feel for what you are up against:

https://www.google.com/search?biw=99...57.xik5WXGykuE




I still have a great condition C4 CAT in my shed!

Bill

 

I have a set off my 2001 coupe/6speed..Pay shipping only. Bill if you need them or a friend --yours ...




Up graded to this.

 

Thanks Bill for all the info you gave me to feed on. Ill check out those Google Images and pics to get a better idea of what might be the best route to take. Those pics of your Z06 exhaust are awesome. Love the way the headers wrap around the engine.Anyway, thanks again. You guys always come through with flying colors.

 

Mike I sent you a PM

 

Please keep us posted with pictures of your project to put the LS1 into your C4.

 

sent you an email