Misfire and Air-fuel ratio imbalance

You probably have a blown head gasket. I tried that Test and still had a blown head gasket

 

Bypass compression and go straight to a leak-down test? This is maybe easier with a Prius too, with the unorthodox start up: one cylinder at a time is pressurized, and then you go looking for air leaks. There's a special gauge as well. Most garages should be familiar with this.

Kind of a long-winded video, he has problems with his (new) gauge, but interesting info:

It seems a common refrain, that coils and plugs are replaced, and turn out to not be a problem. If there's a misfire code for a specific cylinder, just moving the coils to different cylinders and seeing if the code changes is cheaper.

 

I agree with Mendel on a cylinder leak down test. For one thing, you need Techstream to do a compression test.
Second a cylinder leak down test can show air bubbles in the cooling system and help locate where the actual problem is. Read up on cylinder leak down test.

 

Here is one on Amazon.

http://www.amazon.com/SUNROAD-Professional-Engine-Cylinder-Pressure/dp/B071GLQQ1L/ref=asc_df_B071GLQQ1L/?tag=hyprod-20&linkCode=df0&hvadid=312142020868&hvpos=1o1&hvnetw=g&hvrand=2676352272776512267&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9016181&hvtargid=pla-621165318172&psc=1

 

Long after I blew my head gasket, I also ran into the same two codes you did. Only difference was that mine was misfiring on #4. My mechanic tried the old swap the coil trick. I did get the codes back two times, but both of those times they were just the P219A. The misfire code was gone.

It has been over a week now and no CEL since I reset the codes twice after the coil swap.

 

It is unlikely that the P219A is due to coils. This fault generally sets if you have an air/fuel ratio imbalance. The only two causes I can think of, for an AFR imbalance between cylinders, would be a bad injector or a valve sealing issue.

 

Thanks to PriusChat and many of the great users here, I talked to my mechanic about the EGR system, which he didn't realize was different than every other Toyota. The codes (plus the low speed engine rattling noise) were all due to clogged EGR ports inside the intake manifold. We followed Toyota's TSB and replaced the manifold because it would have taken too long to clean, and cost a lot more in labor than the new manifold.

Long story short: new manifold + EGR valve cleaned + we left the EGR cooler alone because it is difficult to clean and will replace it when it needs it = no more rattling noise or codes. All gone. Car drives like new, and even makes a loud intake sound which I never heard before under hard acceleration.

Pictures of each intake port, cylinder 1 being least gunked up, all the way to 4 being most gunked:

 

Good visual.

Clean the whole circuit and you’ll be good to go.

You can always buy spares and have them ready to go for the next round to ensure it is all clean.

 

That's what I was thinking. I will try to clean the manifold, and if I am able to, I can use it next go around then clean the new one I have in there now, and just keep doing that. I may try to do that for the EGR cooler as well. I need to research various ways to clean carbon buildup. At least this way I have the time to clean it and not waste it on labor costs.

You have no idea how relieved I am to be done with that crazy rattling noise...

 

Oh I can imagine the feeling of relief.

I’ve seen that feeling or the smile of avoidance after doing the job.

A pressure washer is the best way for the cooler (you can go the the car wash and use that) and a set of Harbor freight brushes will get the intake manifold good, then finish it off with carb cleaner and you’re all set for the next round.

 

How well do these plastic intake manifolds clean up?. Some plastics are sensitive to harsh chemicals and can be damaged

 

Well I’ve cleaned over a handful with carb cleaner.

As far as getting It spotlessly clean, I leave that to someone more OCD than me.

At the last meetup, @Grit took care of 2 circuits, so he can expound upon the condition pre and post.

 

The intake manifold doesn't mind Oxi-Clean solution. It does mind something like vinegar though: it'll colour the brass-coloured threaded inserts.

The interior of the EGR passages is somewhat rough, impossible to thoroughly clean I found. The main passageways, from throttle body on through, are pretty smooth, and you can get it pristine.

@Raidin having to get a new intake manifold is a bit of a sand-pounder. Maybe he's got the updated number though, so that'll help. Sand-pounder number two: not touching the egr cooler. That should be dealt with asap.

 

He felt that any issue with the cooler will result in a code, so we'll know. If he were to clean it, it would cost me a lot in labor, so I will just have to consider cleaning it myself someday or just replacing it when the time comes. I don't mind spending the money for convenience since my time is so limited.

 

Hello, I know this post is a year old, but I thought I would ask anyways.

Raidin, when you said "long after I blew my head gasket" what do you mean?

Did you have these EGR/manifold problems after you already blew and replaced your head gasket?


I am having the same issues... P219A and now P0301too. But I am starting to think it is a leaking head gasket after all. Because I also have a slow coolant leak somewhere.

I would like to believe that all I need to do is replace the intake manifold and clean the EGR valve and cooler... But I don't want to get my hopes up.

I was gonna have a mechanic clean the EGR system for me because I only had P219a.. but then today I did a test by unplugging the electrical from the EGR system to bypass it... The shuddering/shaking went away completely ... But it started to misfire instead ... So I plugged the EGR back in right away and then the check engine light came on for p0301 too.

I guess it might be worth the money to have a good mechanic diagnose it and tell me if the head gasket is toast or not. But I am curious about what Raidin meant by that head gasket comment.

 

Yes.

I replaced my head gasket at about 375k miles (at the end of February 2018). I didn't run into issues with the EGR until about a year later. It was fixed when I replaced my intake manifold per TSB and cleaned out the EGR valve.

I didn't record when I first ran into this weird sound but it was somewhere around the beginning of February 2019. It flagged a code around mid February, tested resetting codes until mid March just to make sure, and then replaced manifold mid March 2019 at 461k miles.

 

I have used this thread several times now to solve issues. Looking for some advice as I have similar issue. 2012 Prius V 167k miles. Throwing a P0302 and P219A

History:
At around 130k the head gasket was replaced and it had a full valve job.

I have cleaned the entire EGR system within the last 6 months and the manifold within the last month

All coils were replace a year ago when cylinder 3 coil went bad

About 5,000 miles ago the car started to get lower and lower gas mileage but no other indications of anything wrong. That has now progressed to the engine codes above and a slightly rough startup , idle and cruise. It has dropped to a about 35MPG from around 42MPG

I have also checked the wiring for the o2 sensor, MAP and EGR and nothing seems fouled

I am considering replacing the injectors or maybe even the ECU. Any thoughts? Much appreciated.