I Have a 1998 Windstar. When I take the gas cap of a hissing sound occurs, therefore I know that Iu have a venting problem, but what. The code reader gives me code 1450 " Unable to bleed up fuel tank vacuum". Where should I start to find the problem.

 

I would think replacing the gas cap would do it.

 

Might also be a clog in the EVAP system, which vents tank gases into the intake manifold. But as I think about it, the gas cap is probably your culprit....

 

Thanks guys I will try the gas cap for starters. If it doesn't do the trick I will be asking for more help.