Rough idle when rolling to a stop

I’ve got a 2007 6 2.3L manual 230k km and when I roll to a stop the idle bounces and drops a few times for a couple of seconds after fully stopping and is fine after that but happens everytime I slow down just recently started happening after the car sat for 2 weeks the car is throwing no codes.
Not sure exactly where to start looking, this is the first Mazda I’ve owned.
Any help would be much appreciated thanks

 

Have you tried your basics of cleaning MAF and replacing engine air filter? Could also be a vacuum leak, have you checked for any hoses obviously cracked/cracking?

 

Are you coasting in neutral with the clutch released?

Check your battery

 

Yes coasting in neutral, I just put a new battery in the car

 

Battery is bad

 

I literally just bought new battery a couple days ago and battery shows 14.2-14.3 when running so alternator isn’t bad either

 

What does battery voltage drop to when cranking?

EB - why you think new battery bad and not just something choking engine at idle?

 

The described problem has twice been related to a battery with a bad cell for me and at least two other people that have looked for help here

Go to AutoZone and have them hook up the fancy battery/alternator thing. You need to apply a load to see if the alternator is actually good