what would cause the oil light and the gas cap light to be on my 2002 ford taurus

Question

I have bought a new gas cap and a new oil sending unit changed the oil and the lights are still on plus it has a code P1400 on it. please help i'm ready to set fire to it.

Answer 1

P1400 Differential pressure feedback electronic sensor circuit low

P1400 is more than likely the hose that connects to the DPF not being connected or just a failed DPF. As for the fuel cap light the fuel filler neck tends to tear which result in a EVAP leak or a fuel cap light on.