My 2000 Sentra GXE Manual trans, approaching 90K miles recently started having problems with idling upon starting cold. The engine stalls and shuts down if left idling to warm up. I am having to rev the engine to warm up before I drive. Also, the service engine soon light has been on for sometime. I had a dealer recommended 60K service done at 70K miles and the service engine soon light has been on since. Appreciate any advice ...