2002 Ford Explorer code #P1451

need to have it check for trouble codes...most auto parts will do it for free

Here is the definition of the code.
Could be a faulty gas cap, a leak in the evap venting system, a wiring problem, or a faulty vent solenoid. Something caused the system to fail a pressure test.

P1451 FORD Description The Engine Control Module (ECM) detected the canister vent solenoid signal moved outside the calibrated parameters at a specific duty cycle.
Read more: http://engine-codes.com/p1451_ford.html#ixzz27jBna9sq

CHECK WITH CODE SCANNER FOR FAULT CODE/BRAKE LIGHT SWITCH

You need to have computer diag. done, to see why the engine light is on, any auto parts will do this for free, get back with us with the trouble code number, so we can help you diag. your trouble code.

USUALLY THAT MEANS YOUR OXYGEN SENSORS, BUT I WOULD DOUBLE CHECK I WOUNT LIKE TO SPEND OVER $130 ON THAT, THOSE MEASURE THE EMMISION CONSUMPTION AND ADJUST THE PROPER GAS NEEDED TO OPERATE ENGINES EMMISION PROPERLY. ALSO WHO EVER TOLD YOU THAT THEY ALSO SHOULD OF TOLD YOU ABOUT THE BLIND CODES THAT COME UP BUT ITS ACTUALLY SOMTHING ELSE LIKE A CLOGGED CATALIC CONVERTOR ALSO. NEED TO GET A SURE CODE SCAN OR THE ACTUAL CODE NUMBER. USUALLY ITS LIKE STARTS WITH A LETTER "P" FOLLOWED BY A 4 NUMBERS

P0171 - System too Lean (Bank 1)
P0174 - System too Lean (Bank 2)
P1451 - EVAP Control System Canister Vent Solenoid Circuit Malfunction
I'm afraid I don't have enough info to tell you how to fix the P1451 but I'm certain it's the cause of the other two codes.

Go to an autozone they can read the codes and reset the light. They do this as a free service. If there is a problem and you dont repair it the light will return. Sometimes the light can come on for no apparent reason (no code present) a loose gas cap can trigger the check engine light.

do it step by step
p0503
1- change vss sensor and recheck
2- check wiring of vss sensor
p1451
1- check wiring of EVAP vent
2- change Evap vent

Try disconnecting the battery for about 20 minutes or so. This could reset the light. If it does not, call the dealer, service department and ask them to tell you how to reset the light.
I hope this helps you.

Go to autozone (free code check) to get ur engine codes checked out.