2002 Ford Sable P1131, P0301, P0303, P0316 Misfire and Lean Fuel Code Diagnosis

Model: 2002 Sable Fault Code: P0301 Posted: 2011-06-29 15:59

Recently experienced recurring misfire issues on my 2002 Ford Sable, resulting in check engine light activation. I replaced spark plugs, ignition wires, and the coil pack, which improved performance for about 30 minutes before the issue returned. The misfires have since reappeared along with new diagnostic codes: P1131 (heated oxygen sensor malfunction indicating lean fuel condition), P0301, P0303, and P0316 (initial engine run failure). Despite limited budget, I'm seeking advice on potential root causes. Multiple forum posts suggest vacuum leaks as a common culprit—could this be the primary issue? Any insights or troubleshooting steps for these specific codes in a 2002 Sable would be greatly appreciated.