p2187
Moderate
Mitsubishi · Sedans & Cars
System Too Lean at Idle (Bank 1)
Quick Answer
Error code P2187 on your Mitsubishi Sedans & Cars means: System Too Lean at Idle (Bank 1). This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Check for vacuum leaks around intake
2
Test fuel pressure at idle
3
Inspect oxygen sensor operation
4
Check fuel injector spray pattern
5
Monitor oxygen sensor voltage at idle
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 injectors
Vacuum hoses
Fuel pressure regulator
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