I've looked at the FSM and trying to quiet this exhaust noise I have under the hood. The PO removed the stock air cleaner box and put a cone filter on the end of the MAF and a small filter on the end of the hose that comes from this PAIR reed valve thing for air injection. The problem is...at times it appears that the exhaust is coming out this hose, mainly during deceleration and at idle sometimes. By the looks of the book it's supposed to only draw air in ... am I correct on this?

 

any pics ?

 

That hose that goes to the PAIR is actualy sucking. That noise is the sucking into the exhaust. If there is exhaust comming from it the valve is screwed. If you pull the hose and put your hand over it and rev the engine when it is warm you will feel the suck.

 

My truck just started making a loud "exhaust leak" sounding noise, when
i unplugged vacuum line from pair (pulsed secondary air injection) valve the
noise stopped. Gonna check the screws and see if anything came loose, but wondering if anyone has one to sell??

 

PM sent on the reed valve.

 

The reed valve is basically a ... (ready for it) ... reed valve that is supposed to allow air to be sucked through in to the exhaust and block the exhaust pulse when it travels back up the pipe when air is not needed.
The gurgling noise is normal- it's the valve operating. That is why the stock system has a resonator in it (it's the toilet bowl float looking thing to the left of the intake):


But even with the resonator, you can still get some gurgling in the airbox. I kinda like the way it sounds when my 88 does it.