My check engine light came on, truck went in limp mode. The codes are p2509 and p2146. I cleared the codes and unplugged, looked at and replugged the wire plug to the valve cover on the front bank. After driving it down the road a short distance, the truck started running fine. I cleared the code again and let it idle for about 20 min. then drove it a while, everything seems to be ok now. Do I need to replace the valve cover gasket, have it checked by a shop or just drive it? I am 200miles from home. Could it be the gasket or an injector? Oh-this is an 07 3500 drw 2wd g-56 5. 9, stock except for an edge mileage max. Any help will be appreciated.