C5 catalytic converter info
03-24-2007, 01:00 PM
#1
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Thread Starter
C5 catalytic converter info
If anyone can help shed light on this, please chime in. I am trying to understand C5 catalytic converter puzzle. My (limited) understanding of C5 cats:
97-99 utilized a single cat (per side) consisting of a single brick of palladium and rhodium. I am guessing CA cars and rest of nation the same? Anyone have part numbers for these cats?
00 CA and 01 all - two cats per side, small round pre-cat ('pup') very close to exhaust manifold, followed by oval cat similar to 97-99? In 01 the Low Emissions Vehicle (LEV) went national (NLEV) - so all 01's should have the pup and reg cats per side. The pup cat helps light off quicker (from cold starts) I believe, but also add a bit more backpressure due to the added second matrix of catalytic material in the flow.
02 Z06 - went back to a single cat (per side) which has two bricks, first palladium followed by a brick of rhodium. This was done to reduce backpressure a bit and improve performance.
No idea if the 02-04 did same as 02Zo6 or ?
Funny how I don't find much in web searches on this topic, nor can 'regular' Chevy parts guys seem to help. Asked one Chevy parts guy if I could buy a cat to replace one that got damaged - he basically said they only could sell me a full two cat and pipe set from exhaust manifold back to flange for cat back - all for only $1100!!!
I do have a cat with a pn of 25317908 and a 1071F8 below that, but the Chevy parts guys can't even tell me what that pn is for.
If anyone can help educate me, I would be appreciative.
97-99 utilized a single cat (per side) consisting of a single brick of palladium and rhodium. I am guessing CA cars and rest of nation the same? Anyone have part numbers for these cats?
00 CA and 01 all - two cats per side, small round pre-cat ('pup') very close to exhaust manifold, followed by oval cat similar to 97-99? In 01 the Low Emissions Vehicle (LEV) went national (NLEV) - so all 01's should have the pup and reg cats per side. The pup cat helps light off quicker (from cold starts) I believe, but also add a bit more backpressure due to the added second matrix of catalytic material in the flow.
02 Z06 - went back to a single cat (per side) which has two bricks, first palladium followed by a brick of rhodium. This was done to reduce backpressure a bit and improve performance.
No idea if the 02-04 did same as 02Zo6 or ?
Funny how I don't find much in web searches on this topic, nor can 'regular' Chevy parts guys seem to help. Asked one Chevy parts guy if I could buy a cat to replace one that got damaged - he basically said they only could sell me a full two cat and pipe set from exhaust manifold back to flange for cat back - all for only $1100!!!
I do have a cat with a pn of 25317908 and a 1071F8 below that, but the Chevy parts guys can't even tell me what that pn is for.
If anyone can help educate me, I would be appreciative.
03-24-2007, 04:23 PM
#2
Race Director
Looks like you got all the right info. The Z06 had the improved hi-flow single cats in all 50 states, from 02 on.
I suspect that GM may only stock the cats as an assembly. If you need one though, it should be relatively easy to score a set from the parts section.
I bought an entire 03 Z06 exhaust system cats and mufflers and installed it on my 02 vert. It bolts right up and works fine. Every once in a great while, it will throw a code related to catalyst efficiency, but I haven't seen one since I put a new battery in the car. (weird, but weak battery can cause codes to happen). I still have the original pup-cat/cat set in the garage, in case I need them to pass smog in California.
The Z cats are definitely better flowing.
I suspect that GM may only stock the cats as an assembly. If you need one though, it should be relatively easy to score a set from the parts section.
I bought an entire 03 Z06 exhaust system cats and mufflers and installed it on my 02 vert. It bolts right up and works fine. Every once in a great while, it will throw a code related to catalyst efficiency, but I haven't seen one since I put a new battery in the car. (weird, but weak battery can cause codes to happen). I still have the original pup-cat/cat set in the garage, in case I need them to pass smog in California.
The Z cats are definitely better flowing.
03-24-2007, 04:25 PM
#3
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St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12
Looks like you got all the right info. The Z06 had the improved hi-flow single cats in all 50 states, from 02 on.
I suspect that GM may only stock the cats as an assembly. If you need one though, it should be relatively easy to score a set from the parts section.
I bought an entire 03 Z06 exhaust system cats and mufflers and installed it on my 02 vert. It bolts right up and works fine. Every once in a great while, it will throw a code related to catalyst efficiency, but I haven't seen one since I put a new battery in the car. (weird, but weak battery can cause codes to happen). I still have the original pup-cat/cat set in the garage, in case I need them to pass smog in California.
The Z cats are definitely better flowing.
I suspect that GM may only stock the cats as an assembly. If you need one though, it should be relatively easy to score a set from the parts section.
I bought an entire 03 Z06 exhaust system cats and mufflers and installed it on my 02 vert. It bolts right up and works fine. Every once in a great while, it will throw a code related to catalyst efficiency, but I haven't seen one since I put a new battery in the car. (weird, but weak battery can cause codes to happen). I still have the original pup-cat/cat set in the garage, in case I need them to pass smog in California.
The Z cats are definitely better flowing.
03-25-2007, 11:49 AM
#4
Pro
Thread Starter
Larry,
Thanks for the info. Asking because I am putting together my exhaust on my 79 C3 LS1 and want minimal hassle with the CA referee station. PLan to talk to a ref before going in - hope to claim 99 engine, use two cats (no pups) and true duals (like a 99) - might get hassled for conversion having two cats vice one, and different locations. But I think the LS1 needs the cats closer to engine for high temps for the reaction to light off. Funny how CA smog hassles so much when one replaces with new technology that puts so much less crap in the air....
03-25-2007, 11:58 AM
#5
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I don’t have emissions test here. And I really really want to take my cats & precats off entirely to remove the excess restriction of exhaust flow. But I can’t find anyone to delete the systems so I can take them off.
