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
Ignition coil D primary/secondary circuit
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.
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.