I too experienced P1487, P2110, and eventually P2227 coupled with a no start condition in colder weather (below 40*F). I went rounds with the dealership for a while and the problem persisted for almost a year an a half. No driveability problems in the summer months, but when it was below 40*F, the car refused to start. It would crank, but it wouldnt start. And if it did start, it would die.
So here is a condensed version of everything that I did and my eventual solution:
-Did some basic research and found info here and there about it being the PCM failing somehow. So I went to the dealership, and they basically told me "no way, no how." Their lead Mazda Master Tech said it was basically impossible. In all of his years, he had never seen that. So I made an appointment for them to look into it.
-Took it to the dealership who said it was the EGR valve, so they replaced that. Next day it didnt start, so I took it back after doing my own basic troubleshooting in the snow and found the throttle body wasnt opening with the key on to let air into the engine. So they said "sounds like the the throttle body, so we can replace that." At this point, I'm about $1000 into the fix. After the throttle body didnt fix it, I was pissed beyond belief. Then they tried to blame my intake - which is complete and total BS. So I just wrote off the dealership and said screw it, I'll figure this out on my own.
-So this fall/winter, I dug into it. Retraced all of my steps. I replaced the baro sensor, EGR solenoid, and intake vacuum solenoid. Nothing fixed it. I replaced the engine coolant sensor on the side of the engine and did a full coolant flush and replacement. No fix. Electrically tested the crank and cam sensors - they're fine.
-Hail mary: I test for spark (because i assumed the dealership did this) and I dont have spark! Finally, something! So I pull the plugs and they are fine, but the coils arent getting anything during crank. Pull the PCM diagram and that is what sends the signal to the ignition coils. So on a whim I put a space heater in the car and BAM! car fires right up. So I went for a month doing that and I said it has to be the PCM.
-Ordered a refurbed PCM from flagship one inc. for less than $200 with a lifetime warranty. Tried to program the immobilizer and keys myself with a Solus Edge, but Mazda programming HAS to be done at the dealer by a Master Tech. So I go to the dealership and I said "remember me?" and of course they did. So I asked them to just program my keys to the PCM. They did for $90.
-The Best Part: ITS FIXED! I havent had issues with starting besides a day that it was -9*F and my battery died. Other than that, it feels like the car has never run better.
-The problem must have been a failing solder joint or trace on the board that wouldnt make full contact in the cold, but when warmed up it would make contact and fire.