I had a 2001 cherokee and had to replace the coil twice in a few years. They are known to fail. Dunno why Jeep switched to that for the last two years of the XJ. FYI, for those who have 00-01 models and experience misfires after starting up on a warmed-up engine, it's the notorious heat soak issue. There are some fixes that work and some do not. I vented my hood to allow the heat to escape when it's parked after driving. I also had a relay hooked to the electric fan that enabled it to run a few minutes after shut down to cool the engine bay. This corrected the dreaded heatsoak misfire. Just a heads up.

Okay, I have been a mechanic for 0ver 30yrs. I have watched some of your videos, and, would bring things to you for repair. Anyone can plug a scanner in and see the codes, then start replacing parts to no end but, you double check your self and the tools you use. Whenever I am going to replace an expensive part, I will check several different ways to make sure that is the bad part, so as to not be a parts changer. Good job! Your a great mechanic!

it's always a pleasure to watch your video. I own a shop and I actually watch your videos during lunch hour for fun.

You know Eric you are one of the smartest troubleshooters I have watched. Usually I can be way ahead of a lot of mechs. But proving you are Polish was loosing your license one day before you got it back, burning the tires off with Dad's car. When I was a teen I broke the pickup transmission doing very similar stunts and he made me put another transmission for punishment. Taught me a bit and probably easier for me than him in his 50's.

I hardly ever comment to videos but Eric O is the most thorough mechanic I ever seen great JOB Only man I seen that takes pride in his work. The small details is what makes a true professional.

just starting watching your videos about a month ago. have to say I love your attitude. with as stressful as this job is and the hours we put into it it's nice to see the chuckles and positive attitude you have. there really are some days I just want to change professions. keep up the awesome videos my man.

Best mech videos on U TUBE - and from a HONEST mechanic - a VERY RARE combination! You're the best!

Thanks for making this video. I have a misfire on my 01 Cherokee and now Im sure its a bad CP. You saved me all those diagnostic tests

Of course on your spare time, keep up the honest work and videos of your repairs.

Thank you for showing the world that there are legit techs out there mechanics whatever you wanna call him that do care and do the right thing and think about the customer at the same time plus I love your work and on a 2000 Cherokee is that's also what I own

Thanks for the video Mr. O! It's still helping people after several years. Polish engineering at its finest! I just replaced the coil rail in my 04 grand cherokee 4.0 with 230,000 mi I was getting a slight miss at idle that got worse over weeks and finally threw p0306. Plugs only had 6,000 miles on them but, number 6 had hairline cracks in the porcelain (which I think were caused by a bad coil). Replacing that plug made it better at idle but it still had a miss and was knocking when giving it gas while driving. While I wasn't 100 % sure it was the coils, I replaced the coil rail along with new plugs and now it seems to be good

Love those Jeeps and the 4.0l but the coil connector is a giant PITA. Thanks for the video Eric.

had same issue in 99 xj, replaced both o2 sensors, replaced coil, replaced map and crankshaft sensors... the problem ended up being heat soak. I think I have replaced all critical components on xj, should be all good for next owner. Lol

Nicely done Eric and thanks for bringing us along.

I love your videos man quite a bit different than a lot of other channels but you never disappoint with a video haha keep up the good videos and proper work

i watch many auto tech videos and i think yours are some of the best !!! very informative and your video skills are great

I had this happen to me this morning after heading to work, I will be looking to work on this tonight. Thanks for doing this video and giving good explanation of the procedures you did. I can give you some info on the low oil pressure. It's the head...if the head has the 0331 casting number on it then it has small hairline cracks between cylinder 3 and 4. In late 99-01 the 0331 head was used and then in 02 a different head was used.

Excellence. Almost could imagine you were working on mine! Same year, color, 250,000 miles, cylinder and troubleshooting dead end after tune up done by previous owner. Had it 3 years now, love my jeep....301 slightly rough idle the last thing to dial in to move onto trustworty 4WD use and a throw a few dollars at cosmetics. Correct, simple and complete explanation....brief too, Subscribed and Thumps Up for sure.

Another great informative video. So far I have watched all of your video's. Btw I called you a few weeks ago about my ex's 2009 Chevy Impala. It had that po401 code. Well I did what you recommended and it worked. I replaced the secondary air injection valve and the code went away. Thank you for the help and thank you for the great video's. When I get a chance I will make the drive up from Buffalo and come visit. Take care and thanks again.

Great video, I have a 2000 cherokee as well with the exact problem, I verified it was the coil... so I just picked up a good coil at the junk yard for 50$, will be putting it in tomorrow.

Thanks man! Great video! Appreciate you taking the time to share your knowledge

Thank you! I never new how easy this fix could be and you showed me what I was missing when trying to fix my Jeep! <a href="#" class="seekto" data-time="300">5:00</a>

Nice work. Love the 4.0L power band but rough idle seems to inherent.

Very methodical diagnosis. Well done.

Love the Jeep vids. 👍

Best video out of all 20 i seen! Great job bro!

We have a lot of your relations here in Galway,lovely people and great workers.Liked the video.

good repair well done Mr. ERIC and thanks for sharing.

I just started watching your videos. They are great. Wish you were closer.

Well done Eric- Thanks

Recently swapped one of these 4.0s out of an xj with 265k. Remember when they had distributors on them? The good old days. Sweet videos man. Good work

Nice quick diagnosis.

He'll be back come inspection time. Thanks for the video.

Good video! Thanks it helped me diagnose a misfire

Eric, firstly, the Jeep hat is critical for this job because it lets the vehicle know that it ain't dealin' with no pedestrian. Secondly, it is a common practice by Jeep DIY'ers and professionals alike to avoid aftermarket electrical components on Jeeps. They report a higher failure rate with aftermarket and claim that OEM (mopar) components reduces "be backs". Your mileage may vary.

great job Eric just did a Grand Jeep 8 cyl CPS was out acted like starter drag kept shutting off after crank that did fix the problem ... I never seen coil pack like that though glad you got a fix .... have a great day! ;)

Awesome video, Great information... Thanks for the help.. God Bless you ❗✌❗💪❗

South Main Auto Repair, thank you for posting this video. I followed your video and swapped out my ignition coil and 2 weeks later no issues. You helped me out of a tight spot. Only thing, taking out mine was very hard and I actually broke it during removal. I appreciate all you do.

have to say thanks, recieved the sma coffee cup, perfect to hold the java while checking out at your vids , thanks again

Nice video. Six-pack coils. Probably saves the company 30 seconds when they're putting the engine together, but when it comes time to repair, the customer has to pay for six coils, instead of one.

A coil pack. My Wife's 97 Grand Cherokee was a 4.0 L, with wires, cap, rotor, & coil. Easy. Pontiac had a 4 cylinder that used coils on top of plastic with internal connections that sat on the spark plugs at the top of the engine. The misfire was an internal short in the plastic between coils. Lucky only the plastic needed replacing. That was back in the mid 90's we fixed that.

You taught me a ton in just 15 minutes. Thanks man.

Good video, very helpful. Thanks.

You keep teasing us with those shirts! Lol. Always nice to have a quick and easy job once in a while.

got to love quick and easy after that long hard winter.

Its a good thing how you explain things as you go n your preety dam good at what you do thanks for the info n help

Thank you for the video...helped me with my Saturn ls1. 😄👍

Glad you had a nice easy quick fix. I left work with a sore ass from an 05 tribute p0750. Solenoid functions when commanded, fluid is good, ppppfffffffffff!!!!!!!!! I'm surprised you don't have a custom camouflage SMAR hat. Thanks for the video, looking toward to the next one.

This was great, I learned so much! Thanks man.

Awesome video man. I learned a great deal of info to help get rid of this stumbling. Thanks man! 🍺

Thank you for posting !

Well done video, thanks for sharing

Great Video man....pretty straight forward and great explaining along the way. No carrying on about stupid shit. Thanks.

Nice and easy Repair Simple Diag On this one Just a bad Coil good work Eric O was very Entertaining @SouthMainAutoRepairLLC

Thanks Eric great job !! Is it possible the paired cylinder with the #6 coil is still operable and not creating a misfire for the paired cylinder. Was it possible to do a OHM coil reading on the #6 and compare with others for a confirmation ? Thanks again, great video !!

Another job well done 👍🏻☝️😀

Well done! I think the lucky cap helped on this one :)

Good job Mr. " O ".

Great video thanks Eric o

Great video!

There is nothing better than a straight six.

Very good video!

very informative video, well put together too.

Love the video see this what I need a mechanic like you I trust u just watching this video I have blinking check engine gas smell going through my Exhaust I'm lost I smell gas on driver side not valve cover passenger side seems ok I haven't inspected anything I have to watch videos learn step at a time

Great Job Buddy I'm doing the same thing

Had my 2001 Jeep Cherokee coded and it read multiple misfires on cylinder 4. Recommended replacing the valve spring. Sound correct to you? Thanks. Great video by the way.

I got a ripp mods dodge viper coil pack on my 2000xj, it's the dodge viper style but aftermarket high output. It's got plug wires now so that's exciting lol

a simple test to determine if the misfire is electronic or mechanical is hooking up a vacuum gauge. pretty quick way to determine what you should be chasing.

I have a 02 Dakota 3.9l check engine light came on p0306 running rough backfiring/ misfire watched this video I hope it’s the same exact thing on my truck

Good job!

same issue 2000 Jeep Grand Cherokee Misfire only on cylinder 6 changed plugs oil coil and ran injector cleaner.No vaccume leaks.Car runs great for about 100 miles.Engine light flashes at high rpms and then misfires.Compression is all good.Not sure what the issue is haven't replaced or tested the injector yet

You're Polish I take back everything I have said about you been nice watching you're vids take care man..LOL. just kidding again I have learned something about coil packs, thanks for sharing...

Thanks for the video. Can an upstream 02 sensor cause a misfire in cylinder 6. Just curious. Thanks, keep'em coming.

Eric, could you have used an inductive probe + lab scope to check each coil output ?

That's awesome your polish. I am too my last name is wachowiz!!! Love the videos Eric!! Keep up the good work buddy!!!

I had this exact same problem. O2 sensor and all

all jeep and dodge have oil pressure switch problem did he try one . Good job Eric

Thanks for posting. Having issues with P0300's and P0350 codes. Following your troubleshooting is a great help. I just sunk over $2500 between my bike and my girls honda accord so I have to troubleshoot my jeep myself since my emergency money has been spent. Did you make your spark plug tester?

Great video. If I can do it you can do it is inspiring. I Replace my PCM based on code but still skipping. Local mechnic thinks its the head gasket. going to see if its coding tomorrow

I know this jeep is long gone, but on the 4 liters they have a problem with sludge buildup in the oil galley behind the pressure sensor causing a low reading. Might help you out sometime in the future.

Thanks for showing us how to do it! Now, roll in bearings, pull the head and get a valve job, ball hone the cylinders and install some sealed power pistons and new cam and lifters only if needed, add timing set, already have new oil pump, in under $500 Will restore compression and maybe some oil pressure will run like new for years easy, keep running rotella, they need it anyway for the cam Or spend another $1000 and build a 4.6

Haha yeah your pretty good at guessing. I am just kidding but seriously you're a great tech and I learn alot from your videos.

i love the XJ

my 97 GCL pulled up P0300,305,306. also codes for the coil, O2 sensor. I replaced NOTHING but the CRANK POSITION SENSOR and all problems were solved. There's a cheap Lil piece of felt on it that erodes over time....

I keep forgetting to give you the thumbs up but I remember this time

I have a '96 Jeep Cherokee SE 4.0 with a misfire also but mine shuts off too, that's not good going down a Texas Interstate. We've had the vehicle to 4 different shops and was still not fixed , I just changed the fuel pump, strained and I'm fairly sure my son who drives it had the plugs and wires changed. I'm at a loss Smith this Jeep, had it since New and it now has 233,250 miles on it still a decent vehicle until this issue popped up. Any suggestions would be highly appreciated! Thank YouHerb

I like the RIpp coil pack conversion kit for 2000- 01 Cherokee it’s a high performance kit that is awesome “ it’s around 300 bucks

Didn't know the 6 had oil pressure problems, everyone always says how great and reliable they are I have a 96 5.2 with143k and runs great, oil consumption and smooth as glass

Thanks for posting I think this will help me out when I start to work on my Jeep Cherokee. Although I think my

i just bought a 1998 Jeep grand cherokee 4.0.,it idles rough,but runs smooth as soon as you mash on the gas,it runs smooth,i cleaned and re-gapped spark plugs and distributor,i'm starting to think it's the distributor pick-up coil.

I have a 2007 Liberty with a P0300. My son did overhead the vehicle shortly after I changed plugs and coils. The 3 and 5 cylinder plugs had carbon on them and I changed them again. The vehicle will run from about 5 minutes then it will die. I pulled loose the cat on the drivers side and the vehicle ran for about 15 minutes with no P0300. It did set a P0171 code, which I’m fairly sure is because the exhaust was removed. I’m thinking the cat is probably clogged and needs to be replaced. Thoughts? Also, if I replace the cat, should I just go ahead and replace both?

I have a 2004 Jeep grand cherokee thats misfiring and stuttering when you drive. It also spewing gas through the exhaust and seems to lose power. The check engine light is also on. I took it to a repair shop and they told me that I need to replace the entire engine wire harness. I am not sure that that could be accurate.When I changed the spark plugs and the coil pack, it worked fine for a few days but the issue is back again. What would you recommend?

Grand Cherokee Laredo 4.7 2000 - After replacing radiator, passing checks then doing deeper diagnose- Turns out (constant P0307) (and intermitant P0302) after extreme overheat situation, cylinder #7 compression is 30PSi and doesn't climb after reset gauge to 0. Compared to others (80's+ PSI). Don't see off the bat any effect on radiator fluid (cap off) while running, no bubbles or overflow (doing it solo). However, spark plug has tar like buildup within 20miles. At this point; assume either rocker/ lifter popped, Cylinder O-ring is bad, head cracked when overheated. Can I pull the head without major hassle? Should I. Gasket seal is a scary thing. Trade in time? What are your thoughts? Thanks.

Hey South Main I have a 1999 Jeep Cherokee with similar misfire codes but I don't have the coil pack setup, I have a distributor. I'm getting the CEL showing code P0301 cylinder 1 misfire and the engine has a rough idle, stuttering during acceleration. What can I check? I replaced the cylinder 1 spark plug that didn't look all that bad and still present. Would next step be the plug wires and distributor? Thanks for the great videos.

There is a chance the O2 sensor problem was a result of the misfire, Good fix!

Did you buy the Verus new or used and how much did it cost? When the new keys come out each year whats the annual cost to keep it up to date? DOes it work decent with OBD1 GM stuff? I might just get crazy one day and buy one, it's been on my mind

Awesome videos! I'm from down here in Galax VA. I couldn't find your page on Facebook. How do you get the cool South main auto stickers?

I have a 99 grand cherokee with a 4.0 and it's misfiring and if I replace the coil it want even start and help would be appreciated

Thanks man

I figured that there was a dead cylinder due to spark because you said that the check engine light was flashing. The check engine light flashes because the catalytic converter is in danger of being destroyed. Raw fuel can overheat a cat and damage it. So if you see a check engine light flashing more likely than not this is the case.