This is weird.. in these quotes you assume she lives in Australia and start quoting Australian laws.. but in subsequent posts you acknowledge she's in NZ.Entaran wrote: Screamer pipes are illegal. Period. They also make one HELL of a noise, you would be better off getting the wastegate plumbed back into the downpipe for both legalities and your ears.
Skipping a catalytic convertor is a great way to get a defect or a huge fine from your gov't enviromental agency. You can get cat's from "Metalcat" which flow so high they don't impede the exhaust gas and still actually work. Yeah it's like 350-400 bucks but ... upto you. Also cars without cat's backfire when you get off the throttle as the unburnt fuel explodes in the exhaust pipe. HOWEVER, if this car was in australia it wouldn't be required to have a cat by law due to build date, so worth checking :)
FYI, our laws aren't the same as yours. You wont get "defected" or a 'huge fine from the government's environmental agency' for not having a cat converter.
If a car backfires when you get off the throttle simply put it is running rich - having a cat converter in place is not going to fix this. It's well known that unburnt fuel actually does damage to a cat converter, eventually the cat converter will overheat, clog up and be rendered useless if exposed to unburnt fuel for too long.
My Eterna backfired when getting off the throttle with the cat converter fitted, and continued to do so when I removed the cat converter. My VR-4 doesn't have a cat converter and it certainly doesn't backfire when getting off the throttle. I would put the backfiring under throttle-off down to the crappiness of the throttle-body injection system rather than not having a cat converter.
