Yaris sedan sputters after a cold start!! CT Scott pls help if you're out there!!!!

[tyrone_yaris]

Hi,

For some time now my car sputters for several seconds after a cold startup but then it idles fine and runs fine. If I stop and start the engine again the next time, it starts fine without any sputtering afterwards.

Usually happens when the car is parked overnight or for a long period say 7-8 hours. Replaced all 3 spark plugs with Denso Iridium, did a throttle body and MAF sensor clean too. Also put in another battery to see if it was a battery problem but still the same sputtering after a cold start.

What could be the cause of this? CT Scott I wish you could give your opinion too.

Thanks

Tyrone