wu299

iTrader: (9)

I'm looking into buying a random tech downpipe to keep both cats. I was told that having both cats will just shorten the lifetime of the cats. How long do cats normally last?

I'm basically hoping to just to do cobb stage 2 with a gutted uppipe, downpipe, and stock axleback. How likely is it that the cats will burn out?

thanks

MARKSTI

iTrader: (4)

If the car is operating well they should last the lifetime of the car.

Notice i said "IF"...as a missfire or a rich condition in the a/f ratios for a extended period or leaded gas kills cats quickly.

I would check and see if the Random tech downpipe is smog legal here in CA...before you spend $$$ on it

STi-owns-evo

iTrader: (4)

IIRC, state law requires cats to last 100k miles and replaced under warranty if failed prioro to that. That's why on the RX-8 they need extremely strong cats which kill a lot of power since rotarys run very very hot, the cat needs to withstand the heat for 100k miles.

wu299

iTrader: (9)

Thanks for the reply. I'm of the understanding that pretty much nothing is legal anyway. I think I've read enough to know that with two random tech cats, I will definitely pass the sniffer test and I would expect to pass a visual, although that's always a risk.

But I like the environment, so I'll do what I can and still have fun

Group B

iTrader: (3)

California law says that Mass Airflow Meters and the factory catalytic converters must last 7yrs/70k miles, otherwise the dealership must replace them under warranty.

In all other states it is 8yrs/80k miles.