Exhaust Check Valve (used with somg).

[PHOENIX]

I have been trying to get some things cleaned up and working better on the truck. I decided to remove the smog pump system until I get the new exhaust system on. I had some leaks I wanted to get rid of. Well I got the pump assembly off and the rubber hoses that bring air to the check valves. I started the truck and noticed that some exhaust was making it through the check valve. A very small amount, but you could hear the exhaust leak at idle. I know with the air pump running this probably makes no difference. Anyway if I rev'ed the engine it sounded like it was a good leak. Is this normal for these valves or should I buy new ones when I install the new exhaust system? I ended up pulling the injection tubes and plugging the holes for now.

thanks.