My 00 mazda b2500 has been having idle problems for a while now. The easiest way to explain it is, when sitting at idle in neutral and throttling the engine above 3000 rpm and letting off the gas it drops into a very low idle (kinda like a bad load recovery?) Normally I would figure it's an easy IACV replacement. But that didn't help. Neither did the plugs, wires, fuel filter and injector cleaner. I'm at a loss. I have no MIL. Or pending codes. Oh and i've also checked my tps, it's normal. Please help!