Toyota Repair: Air Suction Valve, haynes manual, transmission terminal

Question
I have a 1995 4Runner 3.0 V6, 4wd auto with 122K miles.  I have noticed for some time a popping noise upon deceleration.  At first I thought it might have been the blower for the a/c system or some such.  Since I first noticed it, I have replaced the transmission (terminal torque converter failure).  I also just put in a new radiator, and when checking everything out, I heard a very loud popping in the engine compartment.  I sought out the souce, which is the Air Suction Valve.  I followed the test sequence in my trusty Haynes Manual, and the darn thing just keeps on popping.  None of the local dealers I've spoken to have any idea what to do/  The Haynes manual says this is a dealer only repair.  My closest Toyota Parts Department can get me the replacement valve for about $90.00.  My question is -- how critical is this repair (it seems to effect my idle speed), how difficult is it, is it really a dealer only repair, and is it something that an average home wrench with average tools can do?  Thanks.

Answer
The air suction valve has a cover held on with four small bolts,what happens is that thes bolts come loose and sometimes fall out, the popping noise is caused by the reed valves, they work on exhaust pulses to induce fresh air into the exhaust for emission reasons.
All you have to do is replace the missing bolts and tighten the cover back up.