Hi, I'm trying to identify the cause of a discrepancy in long-term fuel trims on a V6 250 with 130k miles. At idle, the LTFTs are around -15% and -6%; while cruising steadily at 40 mph, they drop to -6% and -2%. Under acceleration, the trims are nearly perfect — the higher the load, the lower the corrections. I performed a smoke test and found no vacuum leaks. The next step was testing the AFR sensors — I recorded their response to changes in the air-fuel mixture. I'd appreciate your input: in your opinion, are the sensors responding correctly?
Greetings from Poland (: