triangle12

Six months ago at 128k miles on my C55, the engine light came on. Code scan at that time came up P0456 Evaporative emission system leak detected (very small leak). I purchased a Dorman purge valve and replaced it on the car. The code stayed, so I then purchased a new gas cap and the code went away. Last night engine light came on and now the code is P0446 Evaporative emission system vent control circuit. It recommends replacing the purge valve. The car currently has 133k miles, so this is only 6 months and 5k miles after replacing the purge valve. Is there a chance I was given a defective part? Or should I be looking into other possible issues? Purchased the part online from Onyx Enterprises and I know Dorman is a lifetime warranty, but not sure they are going to exchange it. I kept the original purge valve and I'm considering putting it back on since that wasn't the initial problem with the first code. Any suggestions??