Hey, I have a problem where my car maybe went into limp mode. The engine won’t rev past 4000 RPM. The diagnostics show the following error codes:

• P0031 - Heated oxygen sensor (HO2S) 1, bank 1, heater control - circuit low Oxygen Sensor Heater Circuit Low Input (Bank 1, Sensor 1)
  
• P0051 - Heated oxygen sensor (HO2S) 1, bank 2, heater control - circuit low Oxygen Sensor Heater (Bank 2, Sensor 1) Circuit Low
  
• P0102 - Mass air flow (MAF) sensor/volume air flow (VAF) sensor - low input Mass or volume Air Flow Meter Circuit Low Input
  
• P0660 - Intake manifold air control solenoid, bank 1 - open circuit
  

I thought the MAF sensor might be bad, so I bought a new original DENSO one, but nothing changed. As for the error P0660 - Intake manifold air control solenoid, I’m not sure where this solenoid is located. Has anyone encountered a similar problem? Or would anyone be able to give some advice?