Random Multiple Cylinder Misfire?

The very first thing to do is to check the condition of your 12v battery. A weak battery is the cause of tonnes of issues with the Gen2 Prius. Search the forum for ways to easily test the 12v battery. 2nd, are you sure you have enough fuel in the tank and is there any chance you've got water in the fuel?

If the battery and fuel checks out, I'd look for moisture where it shouldn't be (like in the sparkplug wells) and damage to the spark plug wires.

 

Check the oil level. Oil change + check engine light = oil overfill.

 

Keep your receipts from the oil change, they can pay for any damages caused by overfilling the oil. Take it to a dealer and let them replace any parts that are now oil saturated in the maf sensor. Seriously.
Also let the dealers equipment read the codes, hopefully the dealer will have delt with an overfilled crank case in the Prii before. And welcome to PC

 

I'd hold off on the high-test fuel, it's not likely to help much of anything. The higher octane fuel just prevents pre-ignition of the fuel in the cylinder. The Prius doesn't have a high-compression engine and you weren't getting a Knock or Ping error code. I would fill up just to make sure you aren't running low on fuel and if you think there is a reason you may have water in the fuel, try one of the commercial gasoline drying additives (like Heet).

 

The iridium spark plug change interval is 120K miles. Unless you know that the plugs have been changed recently, I would agree that the plugs should be replaced now.

It is also possible that water may have entered the spark plug wells for cyls 1 and 2, causing the misfire.

I doubt that the 12V battery is causing this particular problem. Good luck.

 

Before spending much on diagnostics, clear the codes (a ScanGauge is very helpful) and keep track of how often this repeats. Is the sputtering continuing?

I say this because my older car, a '97 with 160k miles, has experienced two episodes of this without known cause, both clearing on their own. One episode was a year ago, repeating only once the next morning. The other was almost a decade ago. But neither episode produced any more than barely noticeably power issues, and could have been fuel problems.

 

I don't think there is anything serious wrong with your car. It may well be a waste of money to take it to someone right now. Yes, you are due for plugs and a new PCV valve, but I'd give it 90% that the codes were solely from the oil overfill, which caused some oil to get into the intake and cause misfiring. You probably need to drain off at least 1/2 a quart, maybe more. Ideally, the oil level on the dipstick is anywhere from halfway to 3/4 of the way up to the top dimple relative to the bottom one. You can clear the code by disconnecting the battery negative cable for 5 minutes, or try turning the car on (Ready) and off three times in a row before the engine warms up, i.e. Ready, wait 5 seconds, power off, wait 1 minutes, Ready, ...

 

I'm not sure that the oil over fill has caused all of these codes to be thrown, but the Prius is very very sensitive to having the crank case over filled and you should get that taken care of immediately. As far as the 12v battery issue goes, due to recent events I am convinced that a weak 12v battery can cause absolutely ANY code or series of codes to be thrown in the Prius which may result in any number of odd behaviors. During my most recent 12v issue diagnosis I'm pretty sure I saw the MFD cursing at me. Check the 12v system anyway!

I've always had my oil changed at the dealer on the Prius for a couple reasons. 1st, my dealer offers maintenance plans for $100, including tax and disposal fees, I get 4 oil changes, 4 tire rotations, and one other service (wipers or air filter). 2nd, if they over fill the crank case and cause an issue, they're easily on the hook. It can be a bit harder to get Jiffy Lube or the type to take responsibility for issues like you're seeing since they don't logically seem to be related.

 

Don't forget to have them do the PCV at the same time.

You'd never need to change out more than one coil pack, unless you found water in more than one spark plug well.

 

Get them to check the oil level and drain it to just under the full line before they fit the new spark plugs. You say the oil is just slightly overfilled now, but we don't know how much oil has already been frothed up and drawn into the intake already. It seems like a recurring theme here, people reporting this type of problem just after an oil change. Too much so to be a coincidence.

BTW. With nearly 200k miles on your Prius you probably should be making fairly regular dip stick checks. Just make sure you check when the car is parked on a level surface and has been switched off for at least 10 minutes (to allow the oil to drain back). You should wipe the stick once and then re-insert it to take a reading. I think it's best to fill it to just shy of the full mark. Better to be a few mm under than to overfill.

 

For $77 I question whether your repair shop is going to use the correct Denso or NGK iridium spark plugs. They will probably use a cheaper plug which will not have as long of a service life.

 

I really doubt a slight overfill will cause a random cylinder misfire. Logically it does not make sense.

Starting with the spark plugs makes sense if they have not been replaced before. The coils can be tested individually and replaced as needed. A s long as the plugs are of the correct heat range and type they should be OK for troubleshooting purposes.

MB860 ?

 

I wouldn't have VIP do it I'd have the garage do it.
Go to an auto parts store and get 4
Denso SK16R11 or
NGK IFR5-A11 plugs. $ 12 each. So for the correct 4 plugs the cost is $50 alone.

Take them to the garage and have them install them and ask them to check for corrosion on the ignitor pack connector ends. That corrosion can be cleaned off the connector ends if not to bad. If so corroded they need to be replaced dealer cost $75 each.
But if an ignitor has failed the car would run really bad from the get go. You would know it. Worse case the ends are just corroded.

Then ask the garage to clean the throttle body and MAF. That's easy and takes 5 minutes. Your way way overdue for a throttle body clean and that can cause all kinds of driveability issues. Like all modern cars the throttle body gets pretty sooty. If your curious about that search my old posts as I have a very detailed post on how to clean the throttle body with pictures.

Your garage should not charge more than $100 for the plugs, and tb cleaning.

And by the way you are way way overdue for a trans fluid change too. And the cv joints and struts are done too. I'm just a ray of sunshine aren't I?

Good Luck!