Engine Codes and ABS Lights

I have a 2002 F150 and it has three engine codes P171-System too lean (bank 1) P174-System too lean (bank 2) and P401-Exhaust Gas Recirculation Flow Insufficient Detected. Plus the ABS light is on. I need some hands on diagonistics to try before i go digging into in replacing intake gaskets and shit. Any Help would be very appreciated. Thanks ya"ll.

Sounds like a clogged EGR valve &/or mount portways. Or a Vac system leak or leakage past the intake manifold gasket. Could be a ruptured carbon canister or a faulty EGR solenoid but those tend to show up as an error code themselves. This is assuming the EGR/lean condition are directly related & the lean condition is not the result of poor injector fuel atomization .