2012 Dodge Ram 3500 6.7L Cummings with engine codes P0191 and P0087

Question

the code P0191? is can that sensor be checked using a ohme meter and what should it read if good or if bad. My 2012 3055 6.7 Dodge Ram has been to 3 dodge shops for a total of 9 times and has cost my over $5300.00. I still get a P0087 code low fuel rail pressure. the in tank has been replaced, the fuel fillter replaced, the CP3 injector pump replaced, the pressure relife valve replaced 2x's, the only thing left is the ECM and the sensor. I think maybe the sensor may be bad but after need working fo 10 mounths do to truck not working. $ is short and can't aford to buy a sensor for $190.00 and not be bad. so I'm thinking there most be a test no?

Thanks
2012 Dodge Ram 3500 6.7 cummings
Raymond

Answer 1

is the truck not under warranty ? 

check fuel pressure and the voltage to the signal and the resistance 

Answer 2

P0087 RAM Code - Fuel Rail Pressure Too Low
Read more: https://www.autocodes.com/p0087_ram.html

P0191 RAM Code - Fuel Rail Pressure Sensor Circuit Range/Performance
Read more: https://www.autocodes.com/p0191_ram.html