Prius Misfire P0300 | Simple Fix

[@nathanhatcher7096]

Great video! I seen many of 2nd gen Prius here south with water that's leaked in around the coils seals causing random missed fires especially with the 04-05 they did not have the drain slots behind the oil fill cap like the 06-09, though a lite coat of rtv on the bottom of the seal fix the issues! Thanks for sharing

[@huntergeorge3909]

I've had to fix this issue twice in my 2012 prius (now has 207k miles) and the second time around was a little different and was driving me nuts. Ended up finding out after I replaced both the spark plugs and ignition coils that my accessory battery was bad as my scanner continued to show a misfire. Once I replaced the battery, the rattling and code was gone. I'm guessing this is due to not enough power getting distributed to the ignition coils and causing issues... I live in DFW area of TX so i'm sure the cold Winter temps didn't help out so much over the past couple years and shortened the accessory battery life. TLDR - make sure to test your accessory battery after replacing spark plugs / ignition coils. If you continue to get a code after doing all of these, try swapping your coils or spark plugs into different cylinders to test if the code changes and one of the replacement coils or plugs are bad.

[@tracyeaglesfc111]

Hello I have Prius 2008 and always has break light on and also ABS light and I can recorded any code on my scanner, how I can fix that problem? Thank you for you help

[@kevincawley5786]

I had my original spark plugs replaced at a hundred and seventy five thousand miles on a two thousand fourteen prius. It was really running rough and that fixed it up well. However, the check engine light came on today. And my mechanic ran a diagnostic. And it's saying 301 code and he's saying to change the coils. The video you showed on the generation that labor wasn't significant. I'm being told that there's significant labor with my two thousand fourteen. What do you think your cost would be for replacing four coils?

[@alainastorino5704]

Thx for the video !!! Q: 2014 Prius V (3) with 3 codes, P0300, P0302, P0304. No codes yesterday after I changed the spark plugs, cleaned out the intake manifold and no coolant leak or loss. Today, 3 codes….. I didn’t change the coils but I was thinking I need to change the fuel injectors????? Any help would greatly be appreciated 👍 Thx….

[@carhub2178]

Yes after all new spark plugs and coils if that don’t fix it change fuel injectors, then if that don’t work. You need to check compression

[@dubiousjesse]

I’m gonna go look at a 2006 Prius with the p0300 code. It has 160k miles. Is it worth buying it and fixing the issue(s)? They only want $2000 as is.

[@prashantkadam6296]

My 2008 Prius with 270k is sluggish, rattles all the time and smokes off the tail pipe. Changed coils and spark plugs and PCV valve, still nothing. Any pointers will help.

[@carhub2178]

Head gasket. Do a head gasket test. More than likely what it is

[@tulovikidu989]

How to clear the code P0301 after I replaced the plug? The engine light is off after replacing the new spark plug.

[@robbiepriddy6790]

I have a 2001 prius and got P0300 and P0301. Replaced all spark plugs ignition coil 1 and fuel injector 1. Now the engine shakes at times. Codes were clear for 2 days but I am now seeing the same codes again. Any suggestions?

[@leshamonbilton6526]

Hey my man, I have a 2012 prius plug in, and I was having the death rattle that's what they call it, so I changed the EGR valve, PCV valve and intake Manifold, and spark plugs. I did that, thinking it would fix the misfire and rattle. Will it did not fix it. The mass air flow sensor and air intake temperature sensor came on. So I changed the mass air flow sensor, and those codes went off, but I'm now getting misfired on cylinders, 1 and 4, I think. All I know is multiple cylinders. Do you think it's the ignition coils that need replacing? That's my next thing to change.

[@carhub2178]

Yes. If you want to make sure it’s the coils, put cylinder 2 and 3 coils onto 1 and 4 and see if the codes tell you that 2 and 3 are bad now. If all the coils are good you will want to do a head gasket test

[@leshamonbilton6526]

@@carhub2178 man, I'm hoping it's not that. I was trying to avoid that.

[@NAGIUXS]

@@carhub2178 how do you do a head gasket test on 05-09? Please also do a video on head gasket test, Toyota here in Maryland is telling $500 just to check head gasket condition. I need to know head gasket condition before spending more money on the car (needs aux & hybrid battery repair, catalytic & muffler change). This Prius has almost 300k miles

[@evelynedwin2472]

hey @carhub my 2010 prius triggered the codes P0403 along with the P0300, P0302, P0304. do you believe that the gummed up EGR is casing the misfire codes? yes. it also rattles for a couple of seconds when the gas engine starts.

[@williammclaughlin2606]

You figured it out yet? Mine rattles too for a few seconds then it runs fine

[@michaelmartinx714]

Everything seems to be either spark plugs or that erg cooler is clogged. The unclogging is a nightmare of a repair, really hoping to do the plugs and see if it goes away. The rattle is really annoying. Just hooked it up and I got these p0300 codes, says nothing about ERG..

[@livegood936]

I have those code and oil in the intake manifold and 3 end of the spark plug cover with oil I don’t know what to replace

[@rarefruit2320]

You need to clean up all of the oil. Replace valve cover gasket and associated parts. Replace PCV valve Replace throttle body gasket Replace intake manifold gasket Clean all parts thoroughly inside and out before re-installing

[@buford3838]

2013 prius gen4 code 302 and 304 do the same to fix

[@carhub2178]

Yes

[@z06cam31]

I dont have any check engine lights on my 2008 prius. But every couple of minutes while the engine is running it will start shuddering and shaking. Not really noticeable while driving but very noticeable at idle. Any idea what that might be?

[@carhub2178]

Check compression on cylinders

[@ravenscail]

A dirty throttle body could cause it to run rough at idle without setting an engine code

[@JamesCampbell-c7n]

Thanks doing it

[@michaelrupp5163]

Have changed plugs and coils and still getting a P0301 after it clean for 3-4 weeks following plugs and coils change. Please advise.

[@carhub2178]

Check compression of the cylinders

[@acesavage7443]

2010, all 6 cylinders are misfiring after getting a oil change.

[@abdullahkamil6690]

I have p0300 for 2011 Prius

[@juniorbroham]

I have a 2006 Prius and got code 300,301, and 303 during idle. Sounded like a thumbing/knocking sound. Is that normal for a misfire ? @carhub2178

[@carhub2178]

Yes that is normal but you need to check compression too on the cylinders

[@rarefruit2320]

Juniorbroham did you find the problem?

[@juniorbroham]

@@rarefruit2320 I changed the spark plugs, fuel injectors, and cleaned the throttle body and it went away. You having the same issue?

[@chileepowdah7389]

You’re saying it’s a possibility that it’s not the head gasket?

[@juniorbroham]

@@chileepowdah7389 it turned out to not be my head gasket.