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Super Mechanic
Super Mechanic, Master technician
Category: Chevy
Satisfied Customers: 17165
Experience:  29 yrs. exp., ASE master, cert. in G.M. electrical, a/c, susspension, brakes, electronic steering
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P0140 o2 sensor CKT no activity (bank1..02 sensor..mass air flow

Customer Question

p0140 o2 sensor CKT no activity (bank1,Sensor2) is it an 02 sensor or is it something to do with the mass air flow
Submitted: 8 years ago.
Category: Chevy
Expert:  Super Mechanic replied 8 years ago.

Hello and welcome to Just, Super mechanic here. About your vehicle.

That would be the sensor itself. However, you will want to check that the wires and connectors are all good. There is always a chance that the PCM has an internal problem but whenever I have run into this, it was the sensor. Here is some of the tests for it along with a wiring diagram. The tests came out in reverse on the paste. You would start at one, (of course)