I have a 1998 Ford Contour SE with 103,000 km on it. I have major fuel problems. I'm only getting 400km per tank. Both O2 sensors and all spark plugs have been replaced. There are no codes. This has been going on for over a year. Any suggestions would be greatlky apprecieated. Thanks.

1998 Contour 1500,000+ kms Power Package Everything Aluminum Alloy Wheels 2.0L Engine Canadian Eh?!