Low Rpms at Idle.

[ProPro5]

While driving , and then comeing to a stop , My idle drops down to around 300 and stays. I apply the gas pedal and it goes back up and then will be around 750. but then drops back to 300. This is not every time I drive but it has happen alot lately. Any suggestions before I take it to Mazda ?

 

[tweety2300]

Well first how do you know its 300 rpm? Our tacks go 0 500 600 etc not to be an ass or anything just an fyi. But id say clean your egr and iac valves its simple and there's a step by step how to on here just search for it in the how to section. But first try unhooking the positive battery cable and switch your lights on let it sit for 5 minutes turn your lights off and reconect not garunteed but simple and free. It fixed mine a few weeks ago

 

[fotomoto]

I, too, had a similar issue and have an ultragauge installed that has a digital tach. Coming to a stop, idle RPM would drop as low as 400, then slowly rise back up to the 700 region, eventually hold and then smooth out. I, too, suspected either the egr or IAC valves. My egr valve didn't look too bad to me but I cleaned it anyway with no improvement. Next, I tried the seafoam treatment as described in the how-to section with immediate improvements that fixed the issues. So, I conclude it was gummed up IAC valving.

If you have a stock air cleaner setup, the rubber tube with the ribs in the middle located between the airbox and throttle body can develop leaks.