Since it's a 95:

Go out and check the secondaries linkage. Make sure both sides are rotated ccw. Turn the key to run and they should turn cw.

Have the intake gaskets been replaced?

Check the PCV elbow (comes out of the bottom of the UIM) for leaks or collapsing.

Was the CAT recall done? Check for underhood sticker.

"Those who cannot remember the past are condemned to repeat it" -George Santayana