2007 e61 p0440
New to this forum. I got a 07 530xi two months ago and the SES light came on a month later. The only code that is showing is a P0440. I also periodically get a message about checking the gas cap. On my last fill-up at the gas station, the car had trouble starting. It took about 3 or 4 attempts before the engine would start.
From what I have read on the forums here and elsewhere, it could be any of these
1. gas cap seal
2. purge valve leaky
3. DMTL pump
4. a crack in a evap hose
The purge valve replacement seemed to be a common fix for P0440 and could also account for the problem starting up after filling up the tank (tank vapors forced into intake if the valve is stuck open)
Could a faulty DMTL pump cause trouble starting up after filling up the tank?
I would also like to know why the other OBDII codes for a big evap leak or small evap leak didn't show up.