engine codes on 1999 Mazda B2500

can somebody tell me what engine code P1506 means

Asked by for the 1999 Mazda B2500
my scanner shows it as idle air control over speed malfunction.check the idle air control sensor to see if its dirty or has a loose connection.if its bad they're $35.99 at auto zone.
when I start my truck it won't idle if I put the gas pedal to the floor the engine rpm revs up then goes right down and then revs up and down exhaust blows out strong fumes If I unplug the maf sensor the engine runs fine but won't idle I did replace the aic sensor and the maf sensor could I have a defective maf sensor
anything is possible with todays technology as far as getting a bad sensor.did you clean the carbon out when you changed the iac?
how do you clean the carbon out you really can't see it's at the back of engine
sounds like a pain then.anyway of getting carb cleaner in an aerosol can to spray it out?or look at it with an inspection mirror to see if its dirty?