P0171 = System too lean (Bank 1)
Look for a vacuum leak before you buy any parts.
Code P0171 means System to lean (bank 1)
po171--- system to lean (bank # 1)
Code 11 is " No crank reference signal at PCM"
P0171 System too Lean (Bank 1)
Trouble code P1621 means: PCM Memory Performance
The PO171 code for a 2001 Volvo S40 indicates a "System Too Lean (Bank 1)" condition, meaning that the engine control module has detected an excessively lean air-fuel mixture in the first bank of cylinders. This can be caused by issues such as a vacuum leak, faulty mass airflow sensor, or problems with the fuel delivery system. It's important to diagnose the underlying cause to prevent potential engine performance issues or damage.
Ignition coil D primary/secondary circuit
Trouble code P1782 means: Pressure switch circuit: 2-4
Trouble code C1287 means: Steering Sensor Rate Malfunction
Fuel mixture is too lean. Could be anything from a vacuum leak, dirty MAF sensor, bad O2 sensor, etc...
It means that the theft computer has detected a malfunction and set a trouble code.
Bank 1 system to lean. I would suspect a vacuum leak. Check under the hood for a disconnected or cracked vacuum line.