Here's some other possible causes that you can check out:
• Intake air leaks. The best way to check the intake system for a vacuum leak is to attach a vacuum gauge to a full vacuum source. With the engine fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be 21 InHg. If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. The gasket may have failed; spray a water mist at the gasket to see if the gauge reading changes. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.
• Defective EVAP control system pressure sensor. For diagnostic procedure testing, reference the FSM.
• Defective intake air temperature sensor. For diagnostic procedure testing, reference the FSM.
Diagnostic procedures are documented in the FSM for your vehicle. You can download a copy of the FSM from this web site:
https://ownersmanuals2.com/. Section EC.PDF is the one you need to read.