It has different definitions for different vehicles, see here engine-codes.com/p1151.html
P1151 and obd fault code solution for a 97 ford ranger
Trouble code P1151 means: Lack of HO2S bank 2,sensor 1 switches,sensor indicates lean
Trouble code P1151 means: Lack Of HO2S21 Switches - Sensor Indicates Lean
Code P1151 indicates a fault with one of your heated oxygen sensors in your exhaust system.
jetta 2001 vr6 code p1151
Trouble code P1151 means: Coolant Path Clog Up for Coolant Heat Storage System
Trouble Code P1151 means:Lack of HO2S bank 2,sensor 1 switches,sensor indicates lean
What does obd code P0740 mean
p1151 bank fuel trim lean. need to check fuel injectors, intake system for leaks and fuel supply- fuel pressure
The P1151 code on a 98 Mustang means that the heated exhaust oxygen sensor is not working properly. Once this is replaced, the code will go away.
plug a obd 2 code reader into your car and activate it.
OBD I, but for the most part, you can use OBD II