Quick Reference Troubleshooting

PO446:
A. Inspect the canister purge valve (CPV) as described in "canister purge valve inspection". Replace valve as necessary.

B. Inspect the "Fresh Air" circuit. Use the "Pressurize/Clamp/Observe" method to isolate a possible blockage by disconnecting hoses at different points, each time farther from the canister.

C. Inspect the canister close valve (CCV) as described in "canister close valve inspection". Replace valve as necessary.

PO441:
A. Inspect the canister purge valve (CPV) for a mechanically "partially open" condition as described in "canister purge valve inspection". Replace valve as necessary.

PO455:
A. Check for a missing/loose gas cap first.

B. Inspect for pinched hoses in the "Purge or Tank" circuits causing a vacuum restriction to DPS.

C. Determine whether the leak is at the front or rear of the car, and use the appropriate schematic to isolate the leak in one circuit at a time by applying hose pinching pliers at different locations until the source of the leak is found. See troubleshooting procedure.

PO442
A. Determine whether the leak is at the front or rear of the car, and use the appropriate schematic to isolate the leak in one circuit at a time by applying hose pinching pliers at different locations until the source of the leak is found. See troubleshooting procedure.

B. For 1998 Elantra/Tiburon with no apparent leak found, verify that the white fill vent valve plunger moves freely inside its cage.

See Fill Vent Valve troubleshooting.

C. For 1998 Elantra/Tiburon with no apparent leak found, verify canister close valve seals properly as described in "canister close valve inspection". Replace valve if necessary.

D. For 1998 Sonata, check for a missing gas cap.