I have 12 v on power side of A/F sensor and also on ground side, what could be the problem?

Question

no power and engine light on

Answer 1

P1135 A / F (airflow) sensor heater circuit malfunction (Bank 1 Sensor 1)

P0172 Fuel Trim Rich Bank 1

Power at one side and ground on the other that correct,

 

What you need to look into is your code condition P0172, this will max out the A/F sensor ( known as oxygens sensor) and cause a P1135.Check the fuel pressure regulator at its vacuum port for any fuel leaking into the intake, Running rich condition needs to be corrected this can also be from a plugged air filter