Originally posted by preylude99
well also.... i need to find out from someone who has a 99 prelude also what connects under the middle of the cold air intake.... cause when i bought the car it came with an AEM cold air intake and one sensor or something that hooks into the vacuum box underneath the intake is disconnected and no box is there...... this could also be the cause of the check light
That is the activation swith for the vacuum system that runs the butterfly valve in the stock air box. Since the airbox is no longer there, it is no longer needed. You also need to make sure the vacuum line in plugged which went to the stock airbox. You can stick something like a golf tee in the end, or trace it back to the TB, remove the entire vacuum line, and cap the nipple at the throttle body.