Stock Cats
 

Thinking about stripping out one of the two cats in the stock downpipe. Probably the second one, has anyone tried this? Looking for a little more HP and sound without the cost of a high flow cat. Any thoughts?

first, I think you might be confused as to the oem exhaust setup, theres 2 cats total, one on each side, right after the exhaust manifold, before the Y pipe. thats it, no pre/secondary cats.

second, dont ruin your stock cats, pick up a set of CNT resonated test pipes, they cost $200 shipped.

Thanks for the clarification, for some reason I thought there were 4

Sorry to jack the thread, but I thought of this when I read the title. Cant you sell your stock cats for a good deal of money? Not necessarily to other Z owners but at a scrap metal yard or something? I remember somebody saying never throw away your stock cats, not just because you may need them someday, but cuz they are actually worth quite a bit of money (the cores or something?).

If the cost of the Hi-flow cats is stopping you, maybe look into selling the stock ones to ease the hit.

Subscribed, because I'm cheap.

will the CNT resonated test pipes give me more sound, or is it better just to go with staright test pipes? Also I already have K&N drop ins, what kind of HP increase should I expect?

They've got to be worth something. They steal them off cars in parking lots here in Phoenix. Haven't heard much about it lately but a couple years ago people were going into movies and coming out and finding their car to be much louder than it was a couple hours before.

yeah there's a small amount of platinum in cats.

You can get atleast $80 from a metal recycler for both cats.

Anyone have experience doing this? Sounds like a great way to get some cash for spare parts to me...

My recycler won't take them, primarily because of the theft issue noted above. I've got a fresh set of Corvette Cats in the garage that I'll probably sell to a california guy who unwittingly bought a modded car...

I would keep the stock cats just in case the HFCs go bad, that way you have a back up plan.

I agree with you, your thinking is more long term. I think selling the stock ones right off the bat is more of a short term idea to lessen the blow of the cost of HFCs. Just would suck not to have the stocks in case something happens as you mentioned.

Depending on what you local pollution test laws are, or could be changed to later, it is a real good idea to keep the stock cats in case you need them to pass the test and get your license renewed. Much cheaper than buying new ones from the dealer if the need arises.

Never sell your stock stuff.

1) the parts aren't worth much

2) You never know when you may need to bring it back to stock either for a sale or an emissions issue

3) Aftermarket parts can be easily sold later

No, you were pretty much correct. Considering which emissions tier this car is in, and that it is sold in the same form in California, you're going to find 2 cats per bank. On these cars, this will be in the form of 2 catalyst bricks per pipe - 1 "pre" cat, 1 "post" cat. It all appears to be 1 unit from the outside, but I'm pretty sure there are 2 catalyst components to each cat pipe.

Removing just one of those bricks but leaving the other one in-tact is a different story... you're probably better off not trying.

Im from PR, there is ways here to get by emission laws. I think if I strip out one brick from each bank would be sort of having a HFC, also from just looking at you cannot tell nothing has been done (for warranty reasons) I will let you guys know after I try it.

No I understand you on that. I'm just referring to what has to come on new cars intended for sale in the US, by law.

But I wouldn't recommend removing just one of the cat bricks. Since the two work in tandem, you may be left with a really rotten smelling car depending on which cat brick you remove. Might as well just remove them both as it will just smell like raw, unburnt fuel then. Better than rotten eggs for sure!

i have an extra pair of cats. there are 4 total. 2 per pipe. there is a cat then the rear O2 sensor then another cat after that. i just gutted the one behind the O2 sensor in both pipes so i dont get a cell. i will let you know about sound level and smell when i install them this week(end). BTW it is kind of a pain in the A$$ to gut them so i hope it's worth it.

uh what? theres 2 cats on our cars - right after the header. i believe there are 2 resonators after the Y pipe, but those are not catalytic converters.

oh by the way...nice job bumping an olddd thread

The catalytic converter section in the stock exhaust has two separate converters build in, one before the bend and one after.

yes, what he said. i know because i just spent 2 hours gutting the secondary ones. i dont think im going to put them on now though. i spent like 2 hours trying to remove the top outer bolt and tore up my hands and arms and could not get it so im not going through all that just to maybe change it back.

Keep your stock stuff. I put on HFCs and after awhile I didnt like the rasp so I was able to put stock cats back on cuz I saved them. That way I wasnt stuck with a sound I didnt like or payed again for a stock item. By the way I have a pair of ERZ HFCs that only have about 1K miles on them for sale. lets say $150.

aye...so even after 1k miles there was still a lot of rasp? :ugh2:

Excellent advice. I keep all my Harley oem parts. Aftermarket parts don't increase the resale value of the vehicle. Take them off and sell sepearately when it's time to trade/sell.

A truckload of cats may be worth something. Platinum is trading at $1600+ an ounce and rhodium is over $2200 an ounce. Darn things are more expensive than gold!

More than I liked but not excessive in some peoples ears.

Get a test pipe because in the future you might want to sell your car and the new owner will want those OEM Cats on the car.