I have a 99 Civic Si with a b16 in it running a p28 with crome. The car has been tuned and i am still currently unable to figure out the idle issue. At idle with all loads off, the rpm's stay exactly where they are supposed to be. If i turn on ANY load, it will start to fluctuate about 500rpm back and forth until i turn the load off. This is a problem because its so bad that if i don't slowly drop the rpm's back down while coming to a stop, the rpm will drop too low and the car will shut off. Also, there are no codes showing up.

Things i've done:
Replaced Alternator
Reconnected/Cleaned all grounds
Replaced IAC valve
Replaced Plugs, wires, cap, rotor

Thanks in advance for any help/suggestions.

 

bump for help

 

anyone???