p0171
Moderate
Mazda · SUVs & Crossovers
System Too Lean (Bank 1)
Quick Answer
Error code P0171 on your Mazda SUVs & Crossovers means: System Too Lean (Bank 1). This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Connect OBD-II scanner and retrieve all stored codes
2
Inspect fuel pressure with fuel pressure gauge (should be 50-60 psi)
3
Test oxygen sensor voltage with multimeter
4
Check for vacuum leaks with smoke test
5
Replace faulty component as identified
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
Oxygen sensor
Fuel filter
Fuel injector cleaner
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