help tracking down a code and evap system probs.
ok so i threw a code today - P4056 which is
Evaporative Emission Control System Leak Detected (very small leak)
description is :
(Also see Notes in P0455 above). Does customer regularly commute on a steep grade (down hill grades in excess of 10%? Has the Leak Detection Pump Operation and Diagnosis booklet (Publication No. 81-170-000606) been used to assist in the diagnosis?
Review and if necessary, perform TSB 18-010-02. Be sure to completely read the TSB. The fix for the condition is a PCM replacement, not a reprogramming of the controller. Be sure that there is not any leaks in the system. This TSB applies in a very limited number of cases and usually in mountainous regions. TSB 18-010-02 Is a PCM replacement correct an erroneous MIL illumination for SAE P0456 that sets when driven on steep grades.
what do you sugest i try first? i got this code once before and i looked at the evap canister under the hood and there was a hose that was leading from it that was cracked and i tookl it off and bypassed it and it went away after clearing the ecu. thanks for the help guys
2007 Ford F150
1990 Mustang GT