P0172 Ford - f250 1996

Question

WHAT IS THE CSUSE OF P0171 AND P0172 AT THE SAME TIME?

Answer 1

P0171 Fuel system lean Bank 1

P0172 Fuel system rich Bank 2

The most common cause for a lean code and a rich code condition would be the MAF sensor, provided there is no vacuum leaks for the cause of a lean condition

Here is a vacuum hose that was broken that cause a lean condition , this vacuum line goes to the fuel pressure regulator, in return the fuel pressure regulator could not work properly as its function is to maintain a set fuel pressure, this resulted in higher fuel pressure. There was 2 code stored in the PCM a P0171 and a P0172