the instructions say to remove this part

what exaclty does it do? and is it not important? looks like a 1 way check valve

 

isn't that where the airpump feeds fresh air into the cat?? does the bonez cat have its own?

 

it came with a large hollow metal tube and a ruber hose adaptor.

i think this part prevents back flow to the air pump, but not sure.

 

Do you get the new metalit version? ...if so, the tube is not used as it injects in between the old ceramic bricks. I was told that 95% of the air is pumped through the exhaust ports and you can block off the tube.

 

it probably connects to the pipe that comes from the airpump. you want the airpump to pump in some cool air to prolong the life of the cat. the cats (and exhaust in general) in a turbo rotary get real hot and eventually the ceramic insides melt clogging the cat.

definitely no "back flow" going on....

 

I hacked the check valve off and reused it by attaching a heater hose from the fitting on the bonez to the check valve. Hope that helps.