2007 Prius idle issue after changing sparkplugs?

Prius with idle noise uphill after spark plug change


I have a 2007 Toyota Prius with 120000 miles. I bought it at 90k and have had no issues until I changed the sparkplugs. Now it makes a noise when I go up big hills, which there are a lot of because I have to drive through the Badlands National Park every day. I thought it could be that I didn’t make the computer relearn the idle, but i dont get how to do that on a prius. All of the Toyota guides say to turn the ignition on and off a few times and then let it idle for 20 mins. You cant do that on a prius though because the engine stops at idle. The plugs were NGK iridium pregapped. Auto Zone said they were compatible. Ideas?

No. 1-2

replaced with oem densos no change. going to switch fuel octane. i havent changed the coolant ever some online geniuses are suggesting that?



get the right spark plugs first, from toyota. Often other brands do not fit or they gave you the wrong number