HomeBrandsMercedes-BenzSedansp0171
M
p0171
Moderate
Mercedes-Benz · Sedans
System Too Lean Bank 1
Quick Answer
Error code P0171 on your Mercedes-Benz Sedans means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
W177W206W214V297A220 2024A220 4MATIC 2024AMG A35 4MATIC 2024AMG C43 4MATIC 2024AMG C63 S 2024AMG E53 4MATIC+ 2024AMG E63 S 2024AMG EQS 53 2024AMG S63 E 2024C300 2024C300 4MATIC 2024E350 4MATIC 2024E450 4MATIC 2024EQS 450+ 2024EQS 580 4MATIC 2024Maybach S580 2024S500 4MATIC 2024S580 4MATIC 2024W223
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 O2 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 machine
3
Clean or replace the mass air flow sensor
4
Check fuel pressure with a gauge and compare to Mercedes specifications
5
Inspect fuel injectors for clogging and test spray pattern
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
P0174P0300P0410P0420P0455
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