No way a cat will get hot enough quickly enough. There are light off cats designed to be directly in the flaming exhaust plume because sometimes it takes a cat that close to the exhaust to clean the air. Not to mention the valves are huge and the headers tubes are giant. I think the entire flat plane idea was to get long tube header performance without needing them.superhero said:Why cant a car like the GT350R come from the factory with long tube headers and have cats bolted up to them. I mean, they go as far as shorty headers. Why not long tube. Im sure the cost should not be anything to even think about. could it just be that with long tube headres, they would be unable to make it emmision friendly? Or is FORD saying heareds are a waste. Eighter way that engine has a sound all of it own!