2013 Prius error code 303.. cylinder 3 misfire

Hello...
I'm new to PriusChat.
My 2013 Prius went in for maintenance yesterday. There's been a ongoing "engine light" error issue
and "cooling fan" error that has been consistent for the past year.

My mechanic (who owns his own 5 star rated shop specializing in Toyota/Lexus and used to work at a Toyota dealership) checked both codes. The "cooling fan" error was first resolved by cleaning the blower fan in the back seat and the cooling fan error still came on. My mechanic says that the fan is running fine.

The"engine light" error came up that the car was possibly running lean. It was discussed to possibly replace the AF sensor. Also the MAF sensor had been cleaned and the "engine light" still came back. He ran tests and could not directly find what was causing the engine light issue to continually come back.

So I received some difficult news yesterday while he was doing my routine oil change and maintenance.
An additional engine error code showed up (along with the same lean code) and this one was a "cylinder 3 misfire". Without delving deeper into the issue he was saying basically this could be a head gasket and/or cylinder/engine job which could run into thousands of dollars! My mechanic said for now to watch the engine coolant level. If it starts dropping to mark the levels. He feels that if coolant is leaking into the 3rd cylinder this could be the cause of the misfire. He said if that's the case it would still involve checking the head gasket, engine, cylinder, etc.. very costly.

To give you a background on the 2013 Prius, I'm the 2nd owner and purchased it Dec.2015 from a Toyota dealer with about 72K miles on it. It's my only car and have been using it primarily to UBER/LYFT.
I'm aware that the value of the car would shoot down with higher mileage.. are you ready for the miles..?
approximately 218K miles. Alright, I know I can hear many of you saying are you nuts, etc..?
Well, I still have $10K left before the car is paid off and I'm certain the Prius value is a few thousand less than my pay off amount.

My dilemma is... I'm pretty much done doing the ride share because of the car's mileage and how much I've driven. With this 303 cylinder misfire code and how much would be needed to possibly fix this issue it seems that it may not be worth holding on to the Prius.

With the exception of a few minor cosmetic dings/scratches.. this Prius Persona package can be rated as very good to excellent condition.

I'm here to get experienced feedback if anyone has/is going through a similar situation.

Appreciate any thoughts about this. ~A~

 

Hello Bisco...
The mechanic and I haven't delved into the "troubleshooting" aspect yet.
There seems to be many variables related to the P300 error code.

For now, he want me to watch the coolant level and see if there's a significant drop.
With the current So.Cal. heat wave, I've been using the AC more and the coolant has been dropping. But I'm attributing this to
the amount of energy the Prius is pulling with my ride share miles and the heat.
I may hold off until Sept. for my next maintenance check up and have him start troubleshooting from there.

Honestly... if it ends up being in the $$$'s of dollars I may have to let go of this purple beauty.
And I'm trying not to add tons of more mileage to the Prius.

 

Thank you NutzAboutBolts!
I have no place to do the oil change at home. The car rests on a driveway that has a incline and with a problematic issue with error
codes I might as well just have the mechanic service it. I obviously put a lot of miles on the car so my wheels need to be rotated, and
brakes checked monthly.

I will mention your suggestions to Joe.
It had major service 1 yr.ago spark plugs replaced, cabin/air filter replaced, inspect steering, suspension, and exhaust components, etc.
A pretty long list of items. Mileage was 164,9432 when the Prius had the major service.

I'm concerned about adding a lot more mileage and not knowing how serious this issue could be.

Also would you think it could be a faulty MAF or AF sensor?

 

Hello The Critic...
I just got off the phone with one of the mechanics and he said that the EGR and Intake Manifold isn't the issue.
They've already replaced quite a few intake manifolds relating to the "misfire code" and the the code still came back.

He still suspects the head gasket leaking coolant into the #3 cylinder. And to work on it would be $3600-$4200.
For now, Gary (one of the mechanics) will opt to do what nutzaboutboltz suggested.
Swapping the spark plugs/ignition coils, clearing the error code, do a compression test, and see how it responds.
He will want to test it out in the AM on a cold start and see of coolant is leaking to the cylinder.

One question.. how is the coolant leaking into a certain cylinder and not the others?

 

Got it! Thank you for your reply.
The mechanic tells me that he will test/swap out the ignition coils and spark plugs and run a cylinder compression test.
About $160.
I'm a bit tight this month, but until I get the car in the shop (later in the month) I'll watch the coolant levels and add water to the coolant if needed.

 

I think he'll be doing similar.. possibly using a scope.
I'm bringing the Prius to the shop later this week to check the engine light code and see if it's still showing the "engine misfire"code.
It probably will, but having 200K+ miles anything can happen.

 

Thank you

Thank you for the reply, CNC97,
I'll be returning to my mechanic today as the engine check light is on and we want to make sure nothing else is showing up.
My odometer is at 219,000+ and I'm now averaging about 36mpg. I'm guessing with one cylinder misfiring that I could be getting the poor gas mileage. I average about 68-70mph while on the freeway. Again all the UBER/LYFT miles has racked up and now I'm facing a BIG decision.
I'm still making payments on this car with about $10K remaining. Honestly, I can't afford a major overhaul on a car.
I was already quoted about $4K for the head gasket/cylinder job. New engine.. I can't even imagine!

I'll follow up on this thread after I speak with the mechanic today. Pins and needles right now!