I just repaired the same problem on my wife's 1994 Quest. there are several small maybe 3-4 inch hoses right under the intake air plenum that crack/rot over time, 2 of them were leaking on her van so I replaced them all. It is a relatively easy job, but often overlooked because of their location
check your o2 sensor...maybe bad and is requiring the engine to give more fuel as the car needs more fuel if its getting less air......