You can buy check valves at Autozone, as well. The intake manifold for the MSP also has barbs on it to retain the hoses properly, as well as the clips. That made taking off Bill's IM a real b****. =)
it does exactly what linux described, i dont see why you think its supposed to "help"
DTC P0455 [FS WITH TC]
<table border="2"> <tbody><tr> <td rowspan="1"> DTC P0455 </td> <td rowspan="1"> Evaporative emission control system leak detected (blockage or large leak) </td> </tr> <tr> <td rowspan="1"> DETECTION CONDITION </td> <td rowspan="1">
PCM measures the fuel tank pressure (ftp1), which is the vacuum when a specified period has passed after the tank pressure has reached the preprogrammed target pressure and purge control valve has been closed when monitoring conditions are met. If fuel tank pressure is above threshold, PCM determines that the EVAP system is blocked or has a large leak.
THRESHOLD VALUE
Fuel tank pressure (ftp1): -1.31.95 kPa {-9.7614.65 mmHg, -0.380.58 inHg}
Threshold valve varies depends on ECT at engine start BARO.
I am going to order mine through Mazdaformance.com. The replacement valve cover hardware from my stealership just cost $130. Bolts and the sleeves. ouch.