Just changed the spark plugs in my Prius prime 2017

Oh yeah I see: Toyota changes the interval, for different States. California for example, classifies it PZEV (Partial Zero Emissions Vehicle), and if you reside there you hold off to 150K miles (no "months" stipulation??). Still, stretches credulity, that the same vehicle, in different States, is to have significantly later spark plug change. Compounding the question: they're insanely durable plugs.


Spark plug replacement | PriusChat

 

125k miles

 

Dealer recommended changing the plugs. 2017 Prius Prime, 103k. They stated I was 40k miles over due.

Like, how do they know that‽ For all they know, the last 100k was in 100% electric mode. A far better measurement would be engine hour runtime.

They also quoted me over $400 to change the plugs. I bought the Toyota plugs via eBay for $65 shipped and did it myself in an hour.

Dealers suck.

 

They do!

I am surprised by the amount of oil deposits on the old plugs. Which oil have you been running? You may want to switch to a higher-quality oil, such as Mobil 1 Extended Performance.

You will probably see a ~ 10-mpg fuel-economy gain with the new spark plugs.

 

From the Denso USA web site:


And from carid.com:

 

"As a thrifty old gear head (translation: cheap SOB shade tree mechanic), I've cleaned, re-gapped, replaced compression washers and re-used worse looking plugs."
We all did that in olden days. Not with modern iridium electrodes.

 

Iridium—the element that was brought to Earth by the asteroid that killed the dinosaurs.

 

14.3 mm hex size, sounds like conversion from 9/16”.

 

Or by a lot of volcanic activity bringing it up from below.

 

We'll need these in the future for more iridium.

DSMO Marion | Xenopedia | Fandom

 

Getting ready to change the plugs on my 2017 prius. Getting nervous... as I have not found a video that does my car specifically or a 2016. I wanted a few answers before I try:
1) how to remove the cowl. I do not think I can bend mine to get them out... and if there is any issue, I wll have to remove it.
2) Anti Seize or not??? one guy said not to use it???
3) Dielectric grease on top or not???

I plan to get the plugs at my Toyota @20 a piece... and ask them to verify the gaps before I take them home.
Also, need to get a torque wrench I can trust. Had a bad one over 20 years ago.

I used to love NGK's esp for watercraft. Outlasted Champions 10x... however, going with Toyotas just because they recommend it.

Hoping to hear from someone... I need to do a lot of stuff and tend to research beforehand, but I am not finding a lot, and (this is scary) I have been finding a lot of these videos leave out KEY information. Stuff that will FUBAR your car if you do not know to look out for them. The videos make complete sense, but there are questions you need to know to ask and they never mention the questions or the answers.

 

It can't be that hard. There's some info in the attached. Note, 4th gen didn't have a pdf version of Repair Manual, and this doc is just sorted alphabetcally, so "install" proceeds "removal".

I'm pretty sure they're installed at the factory with clean/dry threads. Also, If you use any sort of anti-seize, you'd want to reduce torque (value shown in attached).

Same as #2.

Ahh, just check them yourself, gap is in the attached I think. If the gaps are wrong, it's because the plugs were flung at a wall or something: modern plugs are carefully pregapped, and it's best to just leave them alone.