Hello I have a bonez hi-flow cat ready to install but I am missing my exhaust check valve

is there any replacement that is instant (kragen, autozone) so i can put my cat onto the car?

I cannot find that pipe with the check valve on it, and I heard that if i run without the valve, the exhaust will backtrack to the intake and HC levels will rise like crazy

any suggestions?

 

try running your air pump output straight into the cat line... Then the air pressure will always prevent any feed back and even it does, it would feed back just into the air pump