Fuel Trim Analysis Calculator

Diagnose fuel system issues using Short-Term and Long-Term Fuel Trim values from OBD-II.

Bank 1 Fuel Trims

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Bank 2 Fuel Trims (V6/V8/Opposed)

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Leave at 0 for inline 4-cylinder engines
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Operating Conditions

Fuel Trim Reference

Total Trim RangeStatus
-5% to +5%Normal
-10% to -5%Rich - Monitor
+5% to +10%Lean - Monitor
Below -10%Rich - Diagnose
Above +10%Lean - Diagnose
Beyond +/-25%Limit Reached - CEL