p0171
Moderate
SEAT · SUVs & Crossovers
System Too Lean Bank 1
Quick Answer
Error code P0171 on your SEAT SUVs & Crossovers means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
KJKHMJKMKP
Likely Causes
  1. Vacuum leak in intake manifold or hoses
  2. Faulty mass air flow (MAF) sensor
  3. Weak or failing fuel pump
  4. Clogged or dirty fuel injectors
  5. Exhaust leak before the oxygen sensor
How to Fix It
1
Scan for additional codes and freeze frame data to identify operating conditions
2
Inspect intake manifold gaskets, vacuum hoses, and PCV valve for leaks using a smoke test
3
Clean or replace the MAF sensor and check for contamination
4
Test fuel pressure at the fuel rail and compare to specification
5
Check oxygen sensor readings for proper switching behavior
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
MAF sensor
Vacuum hoses
Intake manifold gasket
Fuel filter
Related Error Codes
Video Guides
Loading video guides…
Search more on YouTube →