Every time the transmission kicks down, the oil pressure light comes on w/ do not exceed 2,500rpm, engine fault, service now.
The codes P13D3, P13DC,P164B all came on. The 2 integrated cylinder pressure sensor glow plugs and Oil pressure switch were changed. What can be wrong now.
Please advise, Thanks.

w/engine fault, service now. The 2 cylinder head integrated pressure sensors and oil pressure sensors were changed.