I have engine codes p0171 and p1309. How do I fix these codes?

Code PO1309: Misfire Monitor Failure

Description: When the misfire monitor is disabled,usually due to the input signal generated by the camshaft position sensor, by sensing the passage of teeth from the camshaft position wheel.

Code PO171: System too lean (bank 1)

Description: The adaptive fuel Strategy continuously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit.

Troubleshooting P1309

Possible Causes for code P1309

PCM(power train control module), Mass Air Flow Sensor, Engine Coolant Temperature Sensor, Crank Shaft Position Sensor, Camshaft Position Sensor. Now that we have an Idea of what the codes mean , we need to narrow them down. More than likely the problem is causing both codes to set. Keeping this in mind, lets concentrate on Code P1309. Of the possible causes listed above I see two Sensors that may throw up a lean code. I would look at the MAF Sensor first and then the Temp Sensor. You may find that if you remove the internal Sensor from the MAF Case that some degree has collected on the thin wire. If you find debree, use a Q-Tip to clean it. DO NOT USE CHEMICALS TO CLEAN IT. If no debree is found, try a Known Good MAF Sensor. Still no fix, move on to testing the rest of the Sensors on the list till you find the problem.

Keep in mind that the check engine light will have to be cleared after you have fixed the problem.
Code P1309
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