Unequal Fuel TrimLevels Across Banks

[Rocketeer]

Hello there fellows.
Car started to drive sluggish in low rpm range and hesitating on accelerating a few weeks ago. I checked belt, all vacuum lines, spark ignition and fuel system but couldn't find anything obvious. One thing I see in my forescan is the fuel trim levels and knock sensor values being unequal. I also hear a burst of knock when I accelerate from standstill with moderate pedal input. Knock dies out above 2200rpm. Any ideas why the trims are far apart?
Thanks in advance

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[Cory S]

Trims are fine. Under 3% variance on STFT's is normal. Maybe a bad batch of fuel?

 

[ice445]

The knock values themselves aren't very useful without knowing the threshold where the ECU accepts it as valid knock. The fact that the spark adjust reads zero degrees tells me there is no knock, because at least as far as I understand, if there's a positive value there that's how much timing retard has been applied from actual detected knock. Do you get any value in the knock control while accelerating and hearing the sound you've observed?

Fuel trims are also pretty damn good, STFT+LTFT equals total trim, so both banks are pretty close to 0% correction factor which is ideal. Anything under +/- 5% on the long term side is a non issue, and you'd have to be above 10% to indicate something substantial may be wrong. After all, the whole purpose of that is to function as a correction factor. You won't even get a code to set until it's past 20% in either direction.

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