06-12-2025, 01:13 PM
I don't think that the short term fuel trim (STFT1) number means anything. There is no such thing as short term fuel trim in the LA3 strategy.
The fuel trim in the LA3 strategy is LAMBSE1. LAMBSE1 will be 14.64 when there is no fuel correction. The LA3 strategy will not start to correct the fuel mixture until it detects that the exhaust gas oxygen sensor is working. It wants to see the HEGO1 voltage go above (0.5).
HEGO1 should be between 0 and 1. When the fuel is being controlled properly the HEGO1 should bounce back and forth around (0.5). After the HEGO1 sensor is warmed up a low voltage below 0.5 indicates a lean mixture and a high voltage above 0.5 indicates a rich mixture.
The fuel trim in the LA3 strategy is LAMBSE1. LAMBSE1 will be 14.64 when there is no fuel correction. The LA3 strategy will not start to correct the fuel mixture until it detects that the exhaust gas oxygen sensor is working. It wants to see the HEGO1 voltage go above (0.5).
HEGO1 should be between 0 and 1. When the fuel is being controlled properly the HEGO1 should bounce back and forth around (0.5). After the HEGO1 sensor is warmed up a low voltage below 0.5 indicates a lean mixture and a high voltage above 0.5 indicates a rich mixture.