Test H: Step 2

2) Check Fuel Pressure Check Valve  With KOEO, ensure that fuel pressure remains within specification for approximately 60 seconds. If system holds pressure, but vehicle runs rough or misses, or Codes 41, 42, 91 or 92 are present, go to step 9) for sequential PFI engines, or step 4) for all others. If vehicle is a no start, go to next step. If system does not hold pressure, go to step 6) for all engine applications except sequential PFI. For sequential PFI engines, go to step 9).