can anyone interpret a bmw obd code for me? my '03 X5 is throwing a cel. generic obd reader says P0456. dealer said it was the gas cap, but i'd like to know if they're bs'n me.

thanks.

 

P0456 is Evaporative emissions (EVAP) system - very small leak detected, things to check are mechanical fault, hose connection(s), EVAP pressure sensor

 

soooo ... a "mechanical fault" could be the gas cap. right?

 

it could be mate the gas cap is part of that system, fit a new seal or gas cap then see what happens

 

thanks. it's the stealership's problem for the moment. car's still under warranty, but not for long. i'll be gettin' my hands on it soon. do i hear "supercharger"?

 

get what you can off that warranty, supercharger very nice

 

Do what my father did with his truck - a couple hundred miles before the warranty is over, get everything done. Have it detailed, change the oil, dump the coolant, etc, etc. Try to fit as much as you can on the dealership's bill instead of your's.

 

just tighten the cap and undo the negitive on the battery for like 5 min then reattach it and start the car if it was the gas cap the cel should be gone .... correct me if im wrong but im pretty sure that is the way to go

 

nope it doesnt work on the newer cars "but" if the cap is sorted it should clear the cel light by doing a few drive cycles "drive round" if not the code will need clearing ( the light should go off though )

 

they cleared the code the other day along with a bad rattle in the rear hatch. i was just curious to see if they were telling me the truth, which it appears they were. so far so good, but only time will tell. warranty's good for another 3k miles.

thanks for all the input!