Engine Mechanical problem
2001 Lincoln LS 6 cyl Two Wheel Drive Automatic 79000 miles
My 2001 Lincoln LS has the check engine light on - the codes came back indicating " too lean Bank1" and " too lean Bank 2". My mechanic replaced the plenum gasket on the manifold as where a vacuum leak was located. 2 days later and the light went off again with same codes. Any suggestions?