P0173
PowertrainFuel Air Meteringmoderate severityFuel Trim Malfunction (Bank 2)
What P0173 Means
The PCM detects that fuel trim for bank 2 is outside the acceptable range. This indicates the engine is running too lean or too rich on that bank.
Symptoms
- Check engine light on
- Rough idle
- Reduced fuel economy
Common Causes
- Vacuum or intake air leak
- Faulty oxygen sensor
- Faulty mass air flow sensor
- Fuel pressure problems
Diagnostic Steps
- Scan for stored codes and freeze frame
- Check short and long term fuel trims
- Inspect for vacuum and intake leaks
- Test MAF sensor and fuel pressure
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
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