1996 Ford Windstar P0171 & P0174 Trouble Codes: Causes After Intake Manifold Gasket Replacement
I own a 1996 Ford Windstar with a 3.8L engine. My OBD2 scanner is displaying trouble codes P0171 (System Too Lean Bank 1) and P0176 (System Too Lean Bank 2). These codes appeared after I replaced the six red rubber gaskets between the intake plenum and the intake manifold, as recommended during a diagnostic session at a local shop for $98. The technician identified a vacuum leak in that area and advised replacing the upper intake manifold gasket. Despite this repair, the codes persist. Could there be other underlying causes of these P0171 and P0174 codes on my 1996 Ford Windstar? Any insights or troubleshooting steps would be greatly appreciated.
There is a revised gasket kit available that includes all necessary bolts and seals. Please double-check for any remaining vacuum leaks—ensure the new gaskets are properly seated and all connections are secure. If no leak is detected, proceed with further diagnostics to identify other potential causes of P0171 and P0174 codes specific to 1996 Ford Windstar models.