The iridium tipped OEM spark plugs in a 3rd generation (2012, 2013, 2014, 2015 & 2016) Toyota Yaris with the 1NZ-FE 1.5 liter inline four cylinder motor should last up to 100,000 miles, but they should be checked well before that mileage. Take a look at my DIY instructions for the procedure (with the compatible replacement part numbers) by clicking on the text link or the thumbnail image below.
2012-2016 Toyota Yaris Engine Spark Plugs Replacement Guide
