A few months back. I started having issues with airlock from my fuel tank. When I go to the pump gas, I get about $4 worth of fuel before it clicks (stops) and I can hear air trying to escape. Takes like 5 minutes to put in $20.00 of fuel. I replaced the Filler Tube and Vapor Canister and still has air lock. On top of it. I can tell the car struggles for fuel because once a while (very sporadic every couple days) the car will "hickup" on the highway. it will do it for a while then be fine. Could there be lines plugged? If you have any ideas, let me know Oh and I get this error on diagnostics P1131 Lack Of H02S11 = A HEGO sensor indicating lean at the end of a test is trying to correct for an over-rich condition. The test fails when the fuel control system no longer detects switching for a calibrated amount of time.