KN4 - Check FPRC Vacuum Hose to Fuel Pressure Regulator

- Key "OFF".

- Disconnect and inspect the vacuum hose between the Fuel Pressure Regulator Control (FPRC) solenoid output port and the fuel pressure regulator for blockage, kinks, cracks, etc.

- Is the vacuum hose in good condition?

Yes -- Reconnect the vacuum hose. Go to KN5. KN5 - Exercise the FPRC Solenoid Valve

No -- Service or replace the vacuum hose as necessary. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)