Red Triangle & 0351-0354 - After cleaning throttle body and checking plugs. (scan gauge photos)

Hello!
Long time reader, first time poster.
High mileage (225k+) 2008 Prius. Was misfiring cyl 1+2 and had codes that reflected. Spark plugs were replaced about a year ago, so I just replaced the coil packs. Didn't improve it, but didn't make it worse. Same codes came back. Ran a tank of Royal purple and still codes persisted.

Googled and found that the throttle body could be dirty. It was, so I cleaned it up with throttle body cleaner. And since I was in there, I decided to check the plugs. They weren't bad, but had deposits on them. I cleaned them up and put them back in.

During this period I was thinking of checking the pcv valve, but I was running out of daylight, so I put it back together. Clipped ignition coil pack wires back on, and clipped fuel injector leads back on as well.

Put the filter housing back on and put the car back like it was.

Tried starting the car, and it sounded rough and only ran for about 5 seconds and then turned off.

Got the red triangle, "Problem" on MFD with red car with exclamation on it, abs light, vsc light, and engine light.

Scan gauge says P0351, P0352, P0353, P0354.

Thought maybe I didn't torque the plugs enough, so I took it all apart and checked that and put it back together. Same result.

Took it all apart to see if I missed something, and put back together, same result.

Looked at this morning in the daylight, same result.

Went and bought new plugs, same result.

Switched out 2 coil packs, same result.

Battery voltage is right at 12v.

I'm not sure what to do next. I've googled this all over the place.
Please help. :-(

 

It is possible. I did most of it on a cloth and on a brush, but I did spray some directly on the flap a few times to help break down the stuff on the edges that I couldn't reach.

I've read today that too much is not a good thing.

What's the next step?
Would that cause the P0351-4 error codes?

 

Hello,
Thanks for the detailed reply.
I did not check/clean the MAF. I will do that tomorrow.

I did pull the COP to see if I could tell which was throwing it, but I couldn't determine accurately as it kind of sounded band regardless. I did not swap them around.

I did sense the fuel injectors to be the problem from the get go as well.

Other than searching for disconnected or cracked hoses, I'm not quite sure how else to detect for leaks. All of the youtube videos that I've seen require the car to be running. I can't get this vehicle to stay running past the 5 seconds of startup. I did find a video of a guy blowing cigar smoke into a hose and tracing where the smoke goes. Any tips with this would be appreciated.

Thanks for the PDF as well. I saw bits and pieces of that online. Some of that is beyond me, but I'll do my best to work through it.

I should add that the spark plugs definitely had gas on them, and I could smell gas after the attempts to start the car.

Jason

 

Is there such a thing as the Golden Dumbass award?
@SFO or @bisco

Turns out that cylinder 3 coil pack connector was flipped over and essentially plugged in backwards.

I had just cleaned the MAF and checked for any leaks or tubes disconnected. Was going to go to the back of the engine to see if anything was disconnected and creating an air leak.

I disconnected the fuel injectors and was beginning to unplug the ignition coil packs when I saw it. No plastic tab to press in. It was upside down.

Put it all back together and it started up. A little rough, but it started.

I took it for a drive down the street and out on to the freeway. Prior to the freeway, I noticed it was idling high when I pulled up to an intersection. The idle would go down a little when I put my foot on the accelerator.

It drove fine on the freeway, but when I exited, it was inconsistently idling high. Fluctuating a little.

I drove it back home and turned it off. I turned it back on and let it run. It started normally, but still a little rough. Sounds like it is still misfiring a little.

Going to let it sit for a bit and see what a cold start is like.

I know it'll be a few days before the codes come back.

Thanks!

 

Denso Iridium SK16R11

I've driven the car for about 45 minutes over 20 miles at all speeds.

Too late. I already did that, but now it runs.

Waiting for any codes to repopulate over the next couple of days. So far nothing.
I did purchase the bluetooth ELM scan tool and should receive that tomorrow. I will report back with any more screenshots.

In regards to the LTFT number, I observed it to be over 15% this afternoon.
I do have the fuel injectors to install if you think that would be beneficial.

Thanks in advance!

Jason

 

For those of you that are still interested...

The codes came back today.
Random Misfire
Cylinder 1 Misfire
Cylinder 2 Misfire

I plan on replacing the fuel injectors when I can make time.

I will report back my findings.

Jason