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So can I take that to mean the inlet side of the pump is ahead of the airflow sensor and having that hose open is not letting unmetered air into the intake? I suppose it would have to be, since the air going into the pump never makes it to the intake anyway.


No, you don't have to worry about that at all.
The intake for the pump is not drawn from the air filter box.
The hose that comes from the intake port on the pump has a
little noise and air filter on the end of it and it just clips on to the outside of the air filter box.

1995 Trooper LS auto 3.2 DOHC /w SOHC intake
1989 Trooper 2.6 auto
1989 I-Mark RS DOHC 1.6
1991 Stylus XS DOHC 1.8