My friends nytro is also getting er-1, as soon as you turn the key to on u can hear the fuel pump relay clicking like crazy but can't hear the pump purge. We replaced the relay seeing as this is a common issue and well still same error... We played around with it again.. If we heat up the garage it starts fine. If it's cold it doesn't start. Last night we took the fuel pump from his brothers nytro and the sled starts right away, no codes, no clicking nothing. It was like -22 last night , we didn't heat up the garage and its starts.... So seems like this is a fuel pump issue