clean the pcv valve

I'm not aware of the service bulletin from GM for the pvc valve issues on my car.I bought the car used and don't have and answer to your 2 questions you asked.The car has 122 k on it and I don't see oil leaks yet.I am going to take a 1000 k trip and don't want a oil leak issue while on the road I was going to check it out before it started leaking seeing 122k on it.now.this seems to be a on going issue with these cars I hear.Do you know how or where I can get the info to the (GM service bulletin) or upgraded pvc parts) Any and all info is appreciated thank you::::joe