Loss of power P0304

[nickname]

Pulled onto a highway after filling up, engine misfired and lost power. Flash CEL, meaning there was an engine damaging misfire. Pulled code P0304 - cylinder 4 misfire. Turned engine off, then back on, CEL off but car still misfired under heavy acceleration.

Video attached.

Taking to dealership tomorrow, will update with diag.

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[calonzo]

Pulled onto a highway after filling up, engine misfired and lost power. Flash CEL, meaning there was an engine damaging misfire. Pulled code P0304 - cylinder 4 misfire. Turned engine off, then back on, CEL off but car still misfired under heavy acceleration.

Video attached.

Taking to dealership tomorrow, will update with diag.

Wow! Did you check your VIN to see if that TSB applies?

 

[nickname]

I

Wow! Did you check your VIN to see if that TSB applies?

I have not. Praying Honda will goodwill the repair of my VIN isn't applicable

 

[nickname]

No CEL = no DTC = no diag


Been playing phone tag with the advisor, I'm trying to see if they'll road test it. The hesitation has been happening for a few months now, so I'm praying the car will act up with the tech driving.

 

[nickname]

Update

Service Advisor called on Friday saying I could pickup the car. They were unable to duplicate the concern. Upon driving off the lot, the car lost power and the flashing CEL came back, so I busted a u-turn.

Just got the diag

"Your tech got it to act up reviewed the data and it does indeed need the pgmfi update, ac control unit software update,TCM update, oil change, throttle position reset and PCM idle relearn procedure done. this runs 277.95 plus tax .is this okay to proceed?"

 

[calonzo]

Great! Hopefully it solves the problem.

 

[Neddih]

Update

Service Advisor called on Friday saying I could pickup the car. They were unable to duplicate the concern. Upon driving off the lot, the car lost power and the flashing CEL came back, so I busted a u-turn.

Just got the diag

"Your tech got it to act up reviewed the data and it does indeed need the pgmfi update, ac control unit software update,TCM update, oil change, throttle position reset and PCM idle relearn procedure done. this runs 277.95 plus tax .is this okay to proceed?"

90% of that sounds like something they are obligated to do for you, not pay them to.

 

[nickname]

90% of that sounds like something they are obligated to do for you, not pay them to.

So I looked at the TSB and Honda extended the warranty, but I'm at 185k miles, so I'm over the 150k extension.

"American Honda is extending the warranty on these repairs to 10 years from the original date of purchase or 150,000 miles, whichever comes first."

 

[nickname]

I'm not sure what TSBs I've posted, but they're going off 19-033.

Honda just called saying it might be the injectors, which is a 1,6k repair. But we won't know until the updates are complete

 

[Shankmeyster]

You're kinda SOL with the mileage. Just be happy it made it that long without a major issue. Everyone from day one was crying about oil dilution making these motors have a short lifespan. You've basically proven that wrong. Also, you've pushed out a lot more miles in a short period of time then most.

 

[nickname]

You're kinda SOL with the mileage. Just be happy it made it that long without a major issue. Everyone from day one was crying about oil dilution making these motors have a short lifespan. You've basically proven that wrong. Also, you've pushed out a lot more miles in a short period of time then most.

My thoughts exactly. And these were not easy miles, WOT on the daily.

From reading different threads on this site, I'll be looking at putting in new injectors. Definitely not paying 1,6k for honda to do the R&R tho.

I've asked if any diag on the injectors have been completed and yet to get an answer. Depending on what they say, I may pay to have the updates completed or save the cash and buy the injectors

 

[nickname]

So... service advisor called today...

According to him, it could be the values, rockers, COP, spark plugs, injectors, or another fuel delivery system problem

A.K.A. he wants me to pay for diag on every. F that

Spoke with the service manager, whose also been a tech, and he broke it down.

99% theses TSBs are bs. He called it a bait and switch. Majority of the time, the injectors fail causing this misfire. He's going to have the tech hook up a scope and look at spark, injectors pulse, and compare everything to fuel trim.

I'll keep yall posted

 

[nickname]

Nicholas, about to give youa cal but this is what Sergio stated to me. figured it be easier to just copy and paste. .
"Like I was telling Carina, cylinder a/f tests are not useful on most cars (unless directed to by troubleshooting or a bulletin) and also doesn't automatically condemn injectors. I had Carina check for active misfires, it had no misfires while starting or idling. Since she was busy and I feel like I've been involved now, I took the car to see when it misfires. I found that it only misfires at WOT (wide open throttle) and will continue to do so while staying there. I was able to take a snapshot and noticed it does go lean when it starts misfiring. The misfire was sent in case we want help from Techline.

I came back and noticed the car has an aftermarket down pipe, an aftermarket air box with a relocated MAF sensor. The Venturi pipe where the MAF is located is pretty narrow so this fuel management system may not be able to cope with the parts installed, also there is a possibility of the engine being tuned. Exhaust leaks can change Air fuel ratios depending on where the leak is also. I looked at the troubleshooting for the misfire and this is one of those cars where Cylinder a/f test is not used on. But I still ran it anyway, it passed all 5 times, Techline recommends we run it 3 times in a row at least. I noticed the fuel trim is pretty rich at idle, that would be the only thing so far that would point to injectors but I noticed that before I knew it had aftermarket parts. We can continue troubleshooting, the injectors could be an issue but with a car like this it may be multiple problems including problems installed by performance parts, engine tune, fuel quality, etc. The high flow cat on these down pipes are almost free flowing so there is likely a problem there too. we would need to start with 2 hrs diagnosis ($398 plus tax) and go from there


So, they're pointing the finger at the dp and Cai. I call bs.
Thoughts?

 

[nickname]

Spoke with Honda of America. Turns out the original TSB I posted only covers piston rings. Everything else is out of pocket.

 

[nickname]

I'm talking to the tech. This is what she found

Pulled out the spark plugs and right away found the plugs with some corrosion due coolant/oil mixing together. Went ahead and did a leak/cylinder down test found cylinder 3 measuring 8 psi indicating there’s a leak and all other 3 cylinder passed. I pressurized the coolant system and stuck a camera into cylinder three and found coolant leaking down to the valves will need to start with a head gasket as a FIRST step.

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