I had misfire on cyl 1 ,4 and 6 and replaced all coils with new ones from Ebay ,also put all new copper spark plugs and still had misfire on those cylinders ! The only thing left to replace or repair were the Fuel Injectors ! I put in some Chevron Techron Concentrate Plus Injector cleaner with at least 15 gallons in the tank and almost instantly my engine started sounding better and my Engine Light went out,no More Misfires yet with around 100 miles on it . Anyone with Misfire's on these engines might want to try some of that Type of Injector cleaner first and then if still having problems .start testing the coils ! Also check if your Radiator Fluid Plastic tank is leaking on to your two back 4 and 6 coils which can cause misfires which you either replace the tank or make your own shield that deflects any small amount of fluid down the side of the engine instead of on to your coils and plugs !

Very good diagnosis, never fully trust a scan tool, back up all tests, awesome video, thanks for showing a good coil pattern.

Te Professional text book diagnosis. Love that! Keep doing what you do man. Thanks for sharing your time with us,

I have a 2006 Laredo 3.7L, it looks like the same engine. The check engine light occasionally comes on and goes off. I scanned a P0302 - cylinder 2 misfire. This video helped a lot. Maybe I will just check the plug before I go buying an ignition coil. Thanks for the video and info!

Awesome visual ,clear process, easy to follow.helped me isolate my problem for my next project

My 03 Jeep liberty would run great when first started then after driving a bit would randomly start flashing engine light. Code was p0300. Turned out to be the MAP sensor. I removed it and cleaned it with Map sensor cleaner and re installed. Sensor was filthy inside! Started running better immediately and code went away. Keep in mind my jeep has 239k miles.

I diagnosed my 2011 Jeep Liberty after the same warnings; P0304 in my case; changed coils, plugs, wires, etc etc. Turned out to be the fuel injectors! A little more difficult to put on than spark plugs, but not much more; and Amazon had a set that fell around $15 each! Try replacing them before taking it to the dealership. There is a good video on KZfaq regarding the 3.7L Jeep engines. Always good to check the electrical components while you are at it as well.

Great video man keep them coming!! Simply but with a lot of info and easy to understand.

Great work good to see your channel growing. Cheers!!

Great video brother! Wish more KZfaq video's were done like this one. Keep them coming! Wrench on!

Awesome video. I think you've pointed me in the right direction.

Nice video & diagnosis Tom!

love your videos. keep them coming. they are short and to the point yet still give a ton of information

Thanks very much for this video. Very helpful. I have an 05 liberty that is showing both a P0300 and a P0304 code. I plan on replacing all the coils anyway since the engine has about 150k miles and the coils it has are original OEM units.

i have same problem same year and model , i thought is catalytic convertor ,,thank you i fix my jeep for 10 dollars only.

Very informative video! Thank you very much!!!

excellent job lecturer, i'm following.

Good video keep em coming

Very helpful. Well done 👍

Person most have bin driving around with single cylinder misfire, but when second coil went south vehicle will barely move, I am sure it will be coming back with a cat code very soon ! good video

Great job Tom ☺🔧🚘

Very nice. It was a good video showing a subtle short in the pattern. Untrained guys would miss that.

nice keep the diag vids going anyone can do the other repairs. A hybrid video would be cool

Great job.

I have a 2007 Jeep Liberty, I have Changed All The Spark Plugs, Coil Packs and all 4 oxygen sensors and i am still getting Multiple Misfires?

Thank you for your video. Please Where can I find Spark plugs (to buy) for 2005 Jeep liberty. My car engine check is flashing and sending a P0300 multiple Cylinders misfire detected

My Jeep is having the same issue and I noticed that the coolant reservoir actually will end up leaking a lot of coolant on top of the number 6 cylinder and it pool up inside where the coil/sparkplug sits.

Wish there was an easy way to find a local mechanic that would do the same sort of diagnosis on a vehicle. I wouldn't mind paying $100 an hour if they could get me down to just the actual parts I need. To many mechanics use the replace parts till it works strategy which just wastes money.

Just saw this post. Very common cause caused by a shorted Air Fuel Ratio Sensor . These vehicle uses a Air Fuel Ratio Sensor in place of a O2 Sensor. Find the faulty Air Fuel Ratio Sensor in either bank 1 or bank 2. Lambda in a Fuel Ratio Sensor should be 1. Voltage on Sensor should be 3.Volts if sensor is working properly. If heated circuit is not working computer will cause a lean condition affecting "all" cylinders in the bank . Computer sometimes will not show AF Ratio sensor code. Hope this helps. For all you that don't know how a air fuel ratio sensor works please KZfaq Air Fuel Ratio Sensor. Regards, Atech311

Dude!! Thanks you

I just got a P0300 error followed by a P0302 error. I'm assuming this means a misfire in Cylinder 2?

My Liberty 03 has been misfiring lately but I replaced the coils plugs. 02 sensors , crank and the codes are still saying they need to be replaced

Nice video. Are all six easy to replace? Thank you

I have that problem with my jeep grand cherokee 2008 it has the code p0300 but the gas price is fine, what could be the problem?

I have a blinking check engine light(PO300) and a O2 sensor code,my muffler is BAd you can see inside of it, and when the light blinks I lose power...I'm going to get all the coils and plugs replaced and the muffler..should that do it?

I just got this misfire code, cylinder 4. I pulled the coil pack and looked at the plug. Plug was fine except for a rather large gap, .055 at only 10K miles. re-gapped the plug and swapped the coil with number 2. No more miss-fires. I re-gapped all the other plugs, they were all around .052-055, this sucks for such low milage. I won't be using Denso plugs again. I'll stick with Autolite or NGK.

So has same problem just 2 different cylinder replaced all 6 spark plugs and the 2 coils but still flashing engine light any ideas?

Hello, I have machine Dodge nitro 3.7 ekg. I read all your comments but did not understand what the problem is, Connected the computer, no errors at all, but the engine is a little troit and lights wink, please help

Thank you

My misfire was due to a small crack in my fuel injector gasket (O ring) was a $3 part and fixed myself. I believe it happened because the o rings are old and my engine over heated 3 times

Awesome looking computer or scanner tool

regards,how fix problem p0300 ,i have problem ?

I need to know about 2.8 liter diesel engine and how to change water pump and what all comes with new one

I've been through this PITA. The PO300 is the Jeep Liberty computer's way of saying there's a fuel/air problem but it doesn't know why. The OBD will say random misfire but all plugs, coils and seals are fine. No cylinder is misfiring, just the appearance of one caused by the computer running full rich and cutting the spark to various cylinders in panic mode. If one starts the engine and it runs rough, maybe quits and can smell uncombusted gas, it means some component failure caused the computer to lock on full rich. Shut the engine before it eats the seals. It's not a misfire. If it were the computer would specify the cylinder. Usually, the issue is the MAP sensor fried or clogged. Or the MAF. And there are others. A pro mechanic will hook a scanner up and identify the issue in a few seconds. The computer strives to achieve 14.7:1 fuel/air ratio. When any sensor or relay kicks the bucket, it sends the computer into a tizzy that sends out bogus diagnostic info. Disconnect the battery, let the computer calm down, reconnect.the battery, plug in the OBD-II, turn the ignition to pre-start and the computer will eventually pinpoint the problem component.

Have u ever had a coil melt down? 03 liberty 3.7 cylinder 2

Cly 3 keep misfiring I’ll change it and I’ll go out what could be the problem

Is the ignition drop test safe for the engine? and is it really a simple as pulling the coil wire and if the rpm's drop thats the one you change?

I did one on a 03 jeep today and number 3 misfire straight up line and coil ramp replace coil and plug

So when u do a drop test. The ignition coils that could possibly be bad are the ones that don't drop in the rpms ? Great video by the way. I am working on a 2006 jeep liberty.

Hi What are the code faults? p2096 p2098

MOPAR still runs... go figure.. Need to check mine.. THANK YOU.. '07 Jeep Commander, AWD

For my 2007 Liberty 90,000 miles was the Injector electrics. For some dumbass reason I didn't ohm the #1 Injector leads. When i eventually did, it ohmed at 148 instead of around 12.5. So that explains why I had low rpm misfires under 500rpm. Likely upon startups, bc it started and idles fine. Doesn't miss otherwise. Bought reman Denso 6-pack on ebay for $72. I'm just replacing that one Injector #1 bc I'm like that, so I'm gonna try to do that without having to remove anything but the #1 and #3 coils and fuel rail bolts on both sides. Maybe the air intake if necessary.

I had the same problem. Internal crack in coolant reservoir tank causes coolant to enter right chamber. Coolant exits tank though small overflow opening next to firewall, and leaks onto #6 and #4 coil, shorting them out. Solution, replace coolant reservoir tank, and #6 coil in my case. #4 coil also could be damaged also.

Have code faults for #1 misfire, fuel injector 1 circuit open, and Bank #1 lean. There is a slight rough idle, but no misfire perceived, and it runs fine under load and high speed. Doesn't burn oil. Gets 15mpg combined mileage. Ran fine when I got it 64,000 miles. Now it has 110,000 miles. It has had this issue for about 10,000 miles. Not getting worse, but so far plugs and coils and cleaning intake hasn't corrected it. I checked and cleaned Injector and Coils wiring connections and they look good too. #1 Injector plug had some oil in it, somehow. Cleaned it very well with first brake cleaner, then electronics cleaner. Let it dry and reassembled. Can bad Injector o-ring cause this? I already ruled out spark plug, coils, valves, and did intake cleaning. I have not checked orings and the wiring from #1 Injector to the computer control. And don't really know how to. Any tips on checking Injector and its wiring and control while it's still in the head? Thanks!

Hi, thank you for the useful video, my question is why it did not show oxygen sensor codes instead of P0300 Multiple Cylinder Misfire? My jeep gave me the same code with a very noticeable misfire, and the dealer charged me $600 for injection cleaning and spark plug replacement, although they were replaced not long time ago. It is still giving me the same code and the same symptoms (misfire) from time to time.

Hello, I just watch your videos and need some insight for I have a 2005 jeep grand Cherokee 3.7 flashing check engine light runs rough-runs like shit as soon as I start it and drive it. It used to have an occasional P0303 and in which I had changed that #3 ignition coil and new set of plugs, worked fine but sometiimes the P0303 comes on and ran ok and cleared it with scanner. Now I get flashing check engine light runs rough-runs like shit as soon as I start it and drive it. I did the drop cylinder test, nothing...any advice would be appreciated! Thanks.

Hello I just finished watching your video. I am having similar issues with my 2005 Jeep grand Cherokee 3.7 intermittent P0303 code., cylinder three misfire. I have change the ignition coil spark plug occasionally. I have tested by putting the ignition coil code. I have even disconnected the connector to cylinder 3 With no change. I can disconnect any other ignition coil cable and there is a drop in rpms. I am thinking about changing the AIC switch at the fuel injector on cylinder three...any other ideas? By the way I will get a check engine light code pertaining to crankshaft sensor in which I changed both crankshaft and camshaft sensors still the occasional P0303 error. My engine was rebuilt 1.5 years ago with 4000 miles plus catalyst converters were changed 1.5 years ago since the rebuild....thanks in advance....

Guessing the coils didn't actually resolve the issue. Getting ready to mess with the O2 sensor located just before the passenger side of the catalytic converter based on research with results provided

i have a 3.7 misfiring and when i unplug each coil i get a rpm drop what would be my next test ? injectors maybe?

Pretty rare to lose 2 coils that are separate from one another

I already changed cylinder 6 but it the car still says cylinder 6 misfired what do I do

What is a P0108 mean

I had a misfire on cylinder 4 on my 2004 Jeep Liberty... I replaced the spark plug and coil pack..(still same problem).. any suggestions anybody???

I replied coils and plugs still have it. Changed all 6 injectors still there ? What's next burn it ?

Couldn't use the scan tool to do the power balance test? or look at misfire pids? Also, I know coils are super common on everything, why did you go straight to coils vs injectors or vacuum leak?

Question I have an 06 jeep srt8 Grand cherokee 6.1l hemi it's at the dealership dey said its multiple misfires said everything is gud maybe the flywheel or the computer for the engine cuz I had it replaced from ah guy in Florida cuz dey discontinue the one for my truck

Misfire #4 cyl. Engine not running rough but light returns. ...replaced coil. Any suggestions?

nice wow

i have a question. i just bought a liberty 3.7 2005. I'm haveing similar issues. but my coolant reservoir have a crack in itand leaks onto the coil 4 and 6. could coolant cause a misfire eventho the boot covers the spark plug. ans 2nd question. on this vehicle it has green coolant in it would that throw off the compression in the fluid

how does a misfire create a lean condition ? it should create a rich condition ( unburned fuel going by the 0 2 sensor

Nice video. My wife has a 2008 liberty with the 3.7. She told me it was shaking and flashing engine light. I fired it up and it was indeed shaking. I scanned it with a cheep scanner and said improper ionization coil in cylinder 3. I pulled the coil off s d pulled the plug out. Seen nothing wrong visually. Put it back together and no more misfires. It’s been 3 months and still no misfires. I did add some dielectric grease to the boot. I wonder how it went from misfire to no misfire,?

will this cause car to run in "limp mode" less than 1500rpms?

I need help

my 2009 liberty has 206k. has a p0300... replaced the usual. still didn't fix the issue.

shorted primary or secondary???

Hello, Would be good to show a proper ignition coil ramp as confirmation.Thanks

Don't believe everything you read i done the same thing and replaced the coil twice and still had a miss fire at the number 4 cylinder on the 3.7 liter !

What if I have a misfire on cyl 2

Jee

I have the same problem with my dodge nitro 3.7L .. after starting engine.. engine check light flashing .. and the engine start shaking .. I don’t know what to do with it .. can anyone suggest a solution.. 🙏🏻

1 3 and 5 for me

trouble codes are engineered for you to start with the lowest number.

Simple if you have the scanner.

Ignition switch. Video for ignition switch

2005 Jeep Grand Cherokee 3.7: I had engine light flashing and then staying on. Only code was P0300. I replaced all the spark plugs and ignition coils. Cleared the code and the flashing engine light came back on the next day and again only code was P0300. I obtained a "FOXWELL FW601 Elm327 Obd2 Scanner WiFi Code Reader Car Diagnostic Tool" and downloaded several OBD apps for my iPad until I found one that would allow me to load the Cylinder Misfire Cyl 1 through Cyl6 so I could see what Cylinders were misfiring. The IOS App was OBD JScan free version. This revealed that Cylinders 2, 4, and 6 had around 50-60 counts of misfiring. Since all three cylinders were are on Bank 2, I decided to replace Oxygen Sensors for Bank 2. I first replaced the upstream O2 sensor for Bank 2 and thank God, its been running fine now for three days. I never replace the downstream O2 sensor since the upstream fixed my issue.

I just switched coils and seen if misfires changed to other plugs. Stayed on same # plugs. Always have blue powder on plugs and wires. These Liberties SUCK! There's something wrong in design . Don't get taken with you need new coils!

That first 1 was almost ok