Hello I have a 05 Mazda 3 2.0 automatic.. It's been stalling lately.. The symptoms are when driving on freeway, & come to stop idle gets erratic & sometimes dies.. Or after a while driving not at highway speeds, when you come to stop, same issue. I have changed spark plugs& air filter 2months ago . Any ideas???

 

maf is my first guess, check engine light on?

 

I had this problem twice in a 6 month period, but had CEL's both times.

The first was the MAF. I bought one and replaced it, but that didn't do anything.
I took it to the dealer who replaced it and 25 miles later the light came on again. The third time was a charm.

The second time (the day before Christmas 2008,) it turned out to be the evap purge valve which is a little plastic check valve and hose near the front of the engine. It cost me $350 including $100 diagnostics, $185 for the stupid little valve and +/-$50 for 10 mins labor. The balance was tax, shop fees, "chemicals," etc. This was the day AFTER Christmas.
Do yourself a favor and if you have the CEL, use the handle of a screwdriver or similar, and smack the valve with it to free it up. Then reset the ECU and see if that fixes the problem. You might just save yourself $350.