Since I've bought my 8 I've had periodic ignition CELs pop up. I'm currently running on my second CAT but I can tell it's being challenged and is most likely on its way out also. I'm planning on pulling the CAT while I still can and keep it on hand for emissions. I'll most likely shell out the coin for a BHR midpipe and ignition replacement. I don't really care about the CEL showing, but I do mind the backpressure of a failing CAT... so the CAT goes.

I'm ok with some extra smell and nighttime flaming at the exhaust tips, but something I just don't know anything about is the amount of vapor visible in the winter.

I usually warm up my car every morning for about 5 minutes, but I wait specifically for the CAT to heat up and activate which seems to clear my backpressure problems. I can tell the CAT is activated because the vapor diminishes almost entirely at 3000 rpm.

I'm expecting that the car will belch more vapor in the winter without a CAT... however will there be a LOT of vapor? Will huge smoke clouds follow me around since there's no CAT burning off the excess fuel? I know the RX8 can toss out epic amounts of smoke and vapor on occassion, so I thought I'd check to see if anyone runs catless in the winter and has vapor cloud issues.

Thanks

 

the startup smoke that people typically experience is nothing more than the car burning off the condensation that has built up in the exhaust system. That is why you see lot more smoke in the winter time. By the time the engine is warmed up, the car shouldn't be smoking, regardless of the emissions systems installed.

 

There was no noticeable change in the "smoke" (condensation) between my healthy cat and the BHR midpipe I have on now. Also, the cold temperatures seem to help quell any flames sprouting from the exhaust. Unless I've just gotten off the freeway or am doing hard driving the exhaust stays cool enough to not throw much in the way of fire (during a warm spell when the day time temperature rose to ~60 F the car exhibited a greater tendency to expel flames on the over run).