Where is the mass air sensor located on a 2002 chevy blazer?

The mass air flow (MAF) sensor is located in the engine air intake between the throttle body and front of the truck.

Could have a vacuum leak , Is the check ENG. light on ? Could need spark plugs, plug wires ,distributor cap . The IAC motors ,idle air control motor passage could be plugged with carbon. Bad mass air flow sensor could do it. Check for critter nests , found that cars that sit for a while , squires and rodents like to make nests under the hood . I have found air boxes full of dog & cat food. They take insulation and make nests. Check the Air Cleaner Restriction Indicator
The air cleaner restriction indicator is located on the intake duct between the air cleaner assembly and the mass air flow (MAF) sensor.
If the area inside of the clear section is green, no air filter service is required. If the area inside the clear section is orange and Change Air Filter appears, replace the air filter.

How to clean mass air flow sensor chevy YouTube

P0101 is the Mass Air Flow Sensor error,
http://www.obd-codes.com/p0101


P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature

The mass air flow sensor is located on the top in line from the air filter, heres a picture of it, remember its clamped into the air inlet hose that goes to feed air to the engine and it goes from the air filter box to the throtlebody.

Ok, it's not the transmission.
P0101 maf sensor ( mass air flow) sensor. Change the sensor, it is located in the air intake hose that runs from the air filter housing to the throttle plate/ throttle body. Disconnect the wire from it and loosen clamps ( if equipped) and pull hose from it.
P0128 thermostat is below temperature specs, change to a 190 or 195 degree thermostat. auto parts store should be able to tell you which one you need.
P0155 the heater circuit in the oxygen sensor is bad, need new one. That is on bank 2 sensor #1. If it is a V6, looking at the engine, it would be on passenger side, screwed into the exhaust pipe near the exhaust manfold.

might want to check your transmission

The mass air flow (MAF) sensor is an integral part of the throttle body assembly and cannot be serviced separately. For replacement of the MAF sensor refer to Throttle Body Assembly Replacement.

MAF - Mass Air Flow sensor is located in the intake tube between the air cleaner and the intake.

MAP - Manifold Absolute Pressure should be attached to the firewall on the passenger side.

you can get faulty mass air flow meters.Make sure you perchaced the original from your dealers.There are a lote of copy types and they are not calabrated to your vehicle.Most copys are not calabrated.