2007 prius misfire

That's a fair bit of miles for the ICE and since you have already replaced the plugs and fuel injectors (assume you used OEM), I would add some seafoam (2-3 cans per full tank) to be sure you don't have any water in your fuel and then check the compression on your engine. You'll need a mini VCI w/Techstream to command it in inspection/cranking mode or you can try just turning the start button on then off shortly after it starts (try to get cranking time the same for each cylinder) but plan on clearing lots of codes after each time you do this. Let us know how you make out and what cylinder pressures you saw.

 

Has anyone checked the coil packs? Easily accessed.

XT1049 ?

 

Seems unusual to have 2 coil packs go bad at the same time but I agree it´s very easy to just swap #2 and #4 over to the other cylinders and see if the misfire follows. If so then obviously replace them.

 

You are right. Not usual for two to go bad. But sometimes a bad coil pack in cylinder can cause other odd behavior. It's any easy thing to try which is why I suggested it.

XT1049 ?

 

Couldn't agree more.

 

By who and how diagnosed the "misfire" and how much were they talking it would cost to fix? Also, how's your mpg? Going down, sameo-sameo or what? I've had a very rough idle when engine first started when cold, and it's gotten to do it some even when warm, rattleing and sounding off a bit. I've also replaced the spark plugs and cleaned very well the mass air sensor and next going to replace the fuel injectors and then the O2 senser, downstream first cause that's what I happened to buy do to reading that the downstream one could affect mpg as I've gone from mid 40's to 36-37, happened a few months ago...no codes whatsoever. car's only got 145K miles and definitely am going to get the HV battery checked out but don't trust the local dealer so will have to drive and hour plus, so be it. Haven't done much except routine maintenance.... does need the transaxle fluid changed, this week. Also, haven't replaced the whatchacallit ICE?? cooland yet, 140K miles probably should do that, eh??? Good Luck,

 

OH, Ed sorry but I meant to ask you did you r&r your injectors yourself? if so how did you shut off the fuel? I seem to remember when I did the spark plugs I mistakenly disconnected a fuel line right there and gas just kind of dribbled out, I've read that the fuel pump should be disconnected or a fuse pulled or something because there's like 40psi on the fuel line, don't know why it couldn't just be pinched off for a bit to stop any fuel?? By the by my Prius has be using a quart-quart n 1/2 every oil change, which i do every 3,000-4,000 miles with regular 5w-30 and been using bosch oil filters but may try Wix next as heard they're as good or better? thanks for patience, Lynn

 

Start by running some Seafoam in you tank (2 for a full tank) to see if it helps (will cure any water in fuel issues) and run the tank right down then run some Techtron injector cleaner (again 2 per full tank) and see how that worked (will help clogged or stuck injectors).

The downstream O2 sensor is only uses to verify the converter is working properly. The upstream (closest to engine) sensor is use for adjusting the fuel trim on the injectors so that one does affect mileage. Make sure to only use Denso or NGK components (plugs, coils, etc) as some aftermarket stuff doesn't play nice and you'll be chasing multiple issues at that point. I would also clean the throttle body (remove the intake and use a toothbrush with TB cleaner). You'll also want to check fuel pressure and run a compression test to rule out any mechanical issues before replacing the injectors (again use OEM parts here). Yes, I would also change the tranny fluid and coolant (OEM Toyota).

Changing injectors isn't too bad and the pressure in the lines will usually bleed off fairly well overnight. No need to pinch off any lines at all (may damage older lines). I would also suggest running synthetic oil since it tends to hold up much better under heat. As fir filters I usually just stick to stock (stay away from FRAM though).

 

could we have a "how to" on the fuel injector replacement as I can't find anything on here about it and very little 'bout fuel injectors which is weird cause what i can find seems to say they are a bit of a problem on the Prius'sss thanks, Lynn