Hello, first post here.

I have an ongoing issue with my 05 Nox. I brought it used 3 years ago and it has 71, 970 miles on it. Check engine light has been coming on for over a month now. The gas cap was broke and has been replaced. Light is still coming on. Codes that have been thrown up are P0442 & PO455. Large and Small EVAP Leaks.

We have replaced the Purge Soleid and within 2 days the light has come back on. The gas cap is a stock GM part purchased from the dealer. I am taking the Nox to my mechanic on Saturday to get the oil, brakes, and air filter changed and I hope to have some ideas on how to fix this thing by then.

We haven't checked the hoses yet but will do that Saturday. I don't want to purchase the EGR Valve unless its a last resort as it is so expensive and I can't afford it. There is something called a check valve at the back of the Nox correct? Is that the official name and is that an easy part to pick up and replace? Any help would be greatly appericated. Thanks.