My grandson has a 99 4Runner with a fuel gauge issue.Sometimes the gauge will go way past full, sometimes just to full. Drops to 1/2 only. 1/2 is not empty, maybe 1/4. Started as intermittent. JT3GM84R2X0050939. I understand there was a tsb about this, b ut I can't find it. It was something about replacing a circuit board in the cluster. We put a new sender in the tank-no change.