When it rains it pours

I love my 2000 windstar SEL it is fully loaded it has every option that was available in 2000 but it is now 7 years old and is starting to have some problems. It has 70000 miles and last winter after driving in a snowstorm the ABS light came on so i put 2 and 2 together brought it in the garage and and dried it out still didnt fix the problem so i took it apart lubed up the connectors and it fixed it for about a 6 months now it is winter here again and you guessed it the ABS light is back on. Also bank 1 and 2 are running lean with excessive spark knock. i replaced the fuel filter but it didnt do a thing. I can go and have the codes erased and the light stays off for about 3000 miles then turns on again and with the same codes. If any of you have any ideas they would be appreciated.
PROUD OWNER OF FORDS AND ONLY FORDS FOR LIFE!!!
from the beginning :d
1973 Galaxie 500
1974 Maverick
1985 Escort (POS)
1988 Taurus
1995 Taurus (best car i ever owned)
1999 Escort
2000 Windstar