I have a 2006 Mazda3 / 2.0L / 5sp manual / 109k miles
Having idle issues some or most of the time. It will drop from 1000rpm to about 750rpm and sometimes bounce up and down in this range.
Does this car/motor have a sensor for that? Or is it built into the throttle body or something?
The only issue I have ever had other than a radiator drain plug I took out to drain the coolant, then it wouldn't screw back in. Ended up getting mechanic to epoxy a plug/bolt in there to keep the coolant in. It hasn't leaked and all is well otherwise. I was told by some that no one uses the drain plug, they just pump it out to change coolant which seems dumb to me. I have no idea what went wrong or why it wouldn't screw back in but didn't want to buy a new radiator. I think you have to remove the front bumper and stuff to replace the radiator!

 

Go to Mazda, get a diagnostic scan carried out, check PCM software & update if necessary. Clean your MAF, Clean your throttle body, disconnect the battery for a few hours, reconnect, idle until it warms up, go for a drive & see how it goes.

 

Thank you for the suggestions