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bob4a3 · 01-19-2019, 02:18 PM

1999 boxster 130k miles Po455 (gross leak) CEL

This is what I've done so far:
Replaced purge valve (engine under manifold)
Replaced Vacuum control valve (on side of EVAP tank)
Replaced carbon canister valve (on canister)
Replaced Fuel Cap (OEM)
Replaced vacuum valve (on filler neck)
Smoke checked the entire system. Took off underneath panels to check for leaks (none)

I'm at a loss. No signs of leaks anywhere. followed all lines as best I could. I have read everything I can find about this but I have done everything recommended.

I know there is a pressure differential sensor under the battery at the fuel tank. Could this be not working properly?

Any help would be appreciated. I'm ready to pull what little hair I have left out!

01-19-2019, 02:18 PM	#1
bob4a3 Registered User Join Date: Nov 2018 Location: SW Florida Posts: 7	What now? 1999 boxster 130k miles Po455 (gross leak) CEL This is what I've done so far: Replaced purge valve (engine under manifold) Replaced Vacuum control valve (on side of EVAP tank) Replaced carbon canister valve (on canister) Replaced Fuel Cap (OEM) Replaced vacuum valve (on filler neck) Smoke checked the entire system. Took off underneath panels to check for leaks (none) I'm at a loss. No signs of leaks anywhere. followed all lines as best I could. I have read everything I can find about this but I have done everything recommended. I know there is a pressure differential sensor under the battery at the fuel tank. Could this be not working properly? Any help would be appreciated. I'm ready to pull what little hair I have left out!