OK My check engine light came on so I took my car to autozone. The clerk said I needed a new Mass Airflow Sensor. I bought and installed a new airflow sensor. I had the check engine light turned off. After 5 minutes the light came back on.

I bought a Foxwell OBDII/ EOBD computer. I hooked this device up to the port underneath the dash. I received 2 codes one was P0171 and P1035. It should be noted I have no clue how to use this scanner that I bought.

I have replaced the O2 sensor on the manifold of the engine. What else should I do?

 

could be ghost readings

you have to clear the codes between each read and fix

if the reader cant clear ...

with radio code in hand if needed
disconnection of the battery terminals should clear the fault codes

you fixed the problem ,,so these codes should come back

Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)

This code refers to the front oxygen sensor on Bank 1. The heated circuit in the oxygen sensor decreases time needed to enter closed loop.

Read more at: https://www.obd-codes.com/p0135
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general code when an 02 sensor fails
P0171 system too lean bank one

https://www.obd-codes.com/p0171