'91 honda with the D16 (and other engines)have the filter under the intake and on the rear face of the block. This is the worst filter location I have ever seen.
There is no way you can reach the filter form above. Unless you have a lift you must crawl under the car and carefully loosen it with a catch basin under the filter.
I suspect Honda expects everyone to take their car to the dealer for servicing... talk about honda, dealer-friendly design.
