RX-8

iTrader: (6)

My stock pre-cat get really hot. Or at least hotter then normal and sometimes glows red. Does anyone no why???

cruser

More than likely it is clogged. Very common and very bad for your engine and turbos. Replace with a downpipe.

JoeD

a clogged pre-cat or main cat could be causing the excessive heat, thus making the pre-cat glow red. get a downpipe.

race1

YUP! clogged like others said, replace with DP, and before you ask, this only effects startup emissions- so as long as you take the car in hot to get it smogged, it will pass perfectly fine. If you get an SS one, get it ceramic or techline coated black, this makes harder to fail a visual inspection while adding even more thermal protection.

technonovice

Yes get rid of the precat, but I have seen downpipes glow too.

RX-8

iTrader: (6)

Thanks guys!! Downpipe it is

BrianK

just to add in my two cents.... just because it's glowing doesn't mean it's clogged. A downpipe glows too and there's nothing in it... It glows because it's the first thing that gets hit by the exhaust coming out of a turbo rotary - which has about the highest exhaust temps of any combustion engine.

However, even if it's not clogged, you should replace it with a downpipe. your engine bay will thank you.

Silver93T

Don't think the precat wuld glow because of all the heat shielding on it, unless it got REALY hot. Maybe near the flanges where it bolts to the motor. Either way, get a stainless downpipe and ceramic coat it. Much better for your motor.