BTW, if you've over-oiled your K&N, you may have contaminated your MAF and/or IAT which would also pop lean codes (since the PCM infers less air flow based on the sensor reading than is actually passing through the MAF). You can eliminate this cause by reading the Barometric pressure from the PCM. If it is significantly low (<26"Hg and you aren't in the mountains or inside a huricane), then your MAF needs cleaning.

1999 Contour SE Sport MTX75 T-Red/Grey
Audio: Pioneer DEH-7400MP (MP3 CD), Pioneer TS-A6857 front & rear, PPI PCX-250, Infinity Perfect 10.1
Other: cup holders, cargo net, Blizzaks, Potenza RE950s