Replaced Spark Plug going bad too early

what's wrong with them ?
the scorched ceramic ?

 

The plugs look ok, more of a problem with your car

 

Toyota recommends Denso SC16HR11 now (slightly hotter than SC20HR11). Not available where you are? Also, they might be counterfeit.

 

The plug is bad with blowby leaking up through the combustion chamber to the ceramic. Most likely counterfeit.

 

The plug is bad. It is leaking.

 

You can search "spark plug indicator" and you'll see what the plug is telling you

 

Well I don't know crap about "counterfeit spark plug's?" So as far as "reading the plug's go?" You most likely lost that opportunity when you tossed the OEM plugs.

So at this point, your looking at more "symptom's." Assuming the plug's are "counterfeit?" Then they have mostly taken out more system's? The plug wires would be shot, and since they are Coil on Plug. Then most likely the Coil Pack's also? And since the plug's are now "Carbon Fouled," the O2 sensors would also be suspect? As well as the MAF or Map ( I don't know which the Prius uses?) and the Cat is in danger.

You need to also check the codes with a OBD II, code reader, to see what else is going on in the ICE? But it's a GEN 3. And most likely unless you have already done it? The EGR, Valve and EGR Cooler are full of sludge? And that could have been the source of the failure of the "OEM," plugs?

In any case "reading plug's," looks like this.
Reading 101: How to Read Your Spark Plugs - OnAllCylinders

 

That plug looks fine, best you can see from the photo's. The browning is normal.
99% of the plugs have that, it's just the heat.
The tip looks like it's still there, the electode hasn't wasted away.
Were you getting codes of a misfire? Why did you pull them?

 

Those plug's look normal, Ok then.

 

it's out of focus, but looks normal. the chocolate/mocha color you see on the ceramic under the ground strap is an indicator of very good mixture/combustion. look up "stoich spark plug" and you'll see what I mean.

I did notice some white/ash coloring on it though. that's usually indicative of using unneeded fuel additives or possibly (but I doubt) leaded aviation fuel.

the dark ring above the steel (towards the coil on plug connection) cool be leaking, but I bet it's just regular old oil burn in on the plugs.

as far as counterfeit.... nah

do you have misfires or combustion related codes ?

 

Real or Fake Toyota parts???

 

Xenon bulbs and spark plugs.. better be carefull when buying