Fault Codes/Rehlko/516663 0Rehlko516663 0UnclassifiedGeneralWhat This Code MeansOffset error on downstream SCR NOx sensor 4Related Rehlko Fault Codes516663 31516666 1516600 4516667 31516600 3A-227600516284 17ACCY PWROVER WARNING516281 15AD63AHETBrowse all Rehlko fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for 516663 0 on your specific Rehlko unit — cited to the OEM manual, not a forum guess.TRY IT FREE