My buddy said you should be able to use ANY 90-98 rear wheel Lexus car sensor. He insists that is what the problem is. He said he has 5 of them and they are ALL bad. Apparently they are very sensitive, more so than the other air flow sensors unfortunately. Not only if you try to clean them, but even if they just simply get dirty. There's got to be someone local that you can coerce into borrowing theirs for the day.
I still need to take a picture of the axle brace for you.