Code P0351 Trouble shooting?
 

Been getting CEL upon reaching 7800-8000RPM on Stg 2 pump gas map. The code is P0351. I understand that this code is related to coils. However, I tried to identify the faulty coil via logging misfire on cylinders. There was no misfire shown on any!

I thought of taking the car to the dealer to inspect the issue, but I couldn't reproduce the code on stock tune even after driving her hard for half a tank. Everything was smooth and fine.

My next 2 steps in this pursuit are gonna be:

1- Use a higher octane gas (VP MS019) on stage 2 tune to determine if this is related to our crappy 91oct PG
2- Switch back to Stg 1 tune and use pump gas and rev her past 8000rpm and know if it's a tune or a mechanical related issue


My tuner suggested that it's most probably a mechanical issue. But I want to make sure of that before deciding to remove coils or inspect injector seals.

The car is running just fine with a bit of rough idle on STG 2 map, stock tune and stg 1 are both idling very smooth.

I appreciate any feedback and any suggestions :)

p.s. This is not another tuner-war thread, just a guy with some issues :popcorn:

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Ummm.... How could you possibly attempt to reproduce a problem seen only at "7800-8000RPM " with a stock tune?

The last digit of misfire codes identifies the cylinder. In your case, it's coil #1, the passenger side front coil.

The code itself is an electrical fault, most commonly caused by a coil starting to fail. If you had failiing injector seals, you would hear a loud popping, and I believe would be more likely to set a P030x code rather than a P035x code.

Easy way to check is to swap coils #1 and #3, and if the code goes away or moves to #3, it's a faulty coil.

Thanks... I guess I'll do so

I thought with hard driving I might succeed :burnrubber:

I was getting this as well. For me it happens when doing 0-125mph pulls. I had it happen on the stage 2 tune and the stock tune. They just replaced it under warranty.

It is just that you cannot GET to 7800-8000 RPM with the stock tune.
You will be bumping against the rev limiter @ ~7400

Coils have their ratings, once you go beyond that they could be damaged. To make it work at load levels not seen at stock or bypass issues with even more aggressive ignition will do it too.
Otherwise there would be no need for aftermarket coils to support higher engine load/power levels.

Well, for his case, if the redline is 600 rpm higher, that would mean that at the highest load, also requiring the highest amp draw would need to fire 10 times more per second?
Yes, you could be right.

So, I started the trouble shooting last night. CEL came back on stg 2 with Race gas, this meant that it wasn't a fuel related issue.

However, a dramatic change to the scenario occurred when I started hearing BACKFIRE in the engine bay during part throttle tapping under load. It was loud and scary! It came on all maps (STG 1, 2 and stock). It's a clear indication (IMO) of injector seal failure. It did not pull a CEL tho.

Car taken to the dealer's for further inspection

Let us know what they find.

So far, they confirmed that it's an injector seal issue. They had a similar issue with another car from my production batch.

Did they tell you why the injector seal failed?

No. I don't think they have a clear reason for it.

I will check the car and will try the same conditions that brought up this CEL

Will you be logging your car as well?

Yes... Anything particular u need me to log?

Just samples of daily stuff, spirited drives as well as balls out WOT scenarios.
Maybe you'll find something.

I've had p0351 before and the firecrackers from leaking DI's as well. Got my car the day it hit the lots.

So, this is how it went:

Drove the car on stock tune for a while to make sure the "injector seal" is fine and the fire cracking sound is gone. Car was smooth.

I still haven't confirmed whether the P0351 code is solved or not, so I flashed the car back to stg 2 and went to reproduce the code under the conditions mentioned earlier in the post and as I suspected, the CEL came back on with the same code.

To make sure whether it was a tune related issue or a mechanical, I flashed back to STG 1 and took her for a test. The CEL came back on to confirm that it was a mechanical issue.

Took the car to the dealer and they confirmed it was a faulty coil. They had it replaced and the code became history. They replaced Cylinder 1 coil. Tried to reproduce the code and thankfully I failed. I guess the car is fixed now and the issue been solved.

I keep getting this code too...randomly, and only when shifting into 4th at redline and at WOT it seems.

I keep resetting it, things are fine for awhile and then BOOM it comes back again.

I've already had the coil pack replaced once, wondering whether I'd be better off upgrading them/DIYing.

Sucky thing is I have headers on the car and a tune; can't reflash it back to stock and roll it into the dealer without it throwing an emissions CEL.

Complicated, these things. Just how bad is this code? Engine death bad?

I was getting this back late last year. They replaced it under warranty no codes since.

I have exactly the same issue as mentioned above.

When driven hard with a e85 tune, I got P0351 codes. It usually popped up at around 6'000rpm, after a WOT, and when I release the accelarator.
I flashed back to standard tune, and managed to have the same code, though it was harder to make it pop up.

I got a coil pack replaced, but this has not changed anything - still got P0351 code with e85 tune 3 days later. I did not test with standard map yet.

Otherwise, car is running fine. No issues, nothing.

Hey

I also had this code twice within the last 2 weeks as well a P0354 back in April. My car is completely stock at 51000 km. I only drive it on the street. The code seems to come in when accelerating hard through 3rd than shifting to 4. I think I'm going to mention it to the dealer. Are the new coils any better?? If they do have to warranty them, is it worth it to also do the plugs at this stage?

Same issue, same driving style, though mine is ignition coil #1, P0351, last digit is cylinder number, get it replaced it should go away.

Hmm......not good.

Two of them were P0351, and one was P0354. Regardless I think issues are starting to pop now that my mileage is getting up there. I'm going to call mg dealer and mention it to them, and go from there.

Wow 2 coils, yeah take it to the dealership would be my advice.

The coils are going bad due to heat. I was able to replicate my coil issue with the stock tune as well as my tune tune. Get the engine nice and hot and it will do it for you.

I ignored the code for a long while and now I'm not getting any CEL's but the car is mis-firing (no backfire or firecrackers or popping just that stuttering) and a lot of hesitation as if im not accelerating and there is no power to the engine, could this still be an ignition coil issue?

Had a couple episodes of CEL P0351. Took the car to the dealer. Dealer says that it isn't likely the coil, but they want to drive the car and test it to see if a "pin" in the harness is causing the problem.

Anyone know what they are talking' about?
Does this make sense?

Dealer claims they called the Subaru national hotline, or whatever it is.

Thanks

Are there proven aftermarket coils yet? Or have the new factory coils been improved on from 2012 build dates?

dont know how proven they are but freakin expensive

http://www.brz-parts.com/pd4004901r.html

http://www.maperformance.com/cusco-d...cion-fr-s.html

If it heat you reckon is killing them might be worth investigating ceramic coating/wrapping headers or extra ventilation

Wow, that is pricy!

I was thinking if I increased ventilation that should be sufficient, but hard to say if it would solve it completely as I'm still stock.

Thanks though. Maybe the stock ones have an improved insulation.

I have this issue today at the track, it's 97 degrees outside and I am running an E85 tune. Popped up (0351) in session 3 but there was no other symptoms other than the cel. I shut the car down, cleared the code then 2 hours later it came back in session 4. again I cut the session short and decided I would check here to see if this is a common problem.

This is the second time since i got the car that i have gotten this code. :(
i have 30,000 KM on the car.
Hopefully they change the coils

hi Bahraini86

I'm using Open flash Tablet tune my fr-s, stg1, i have the same problem with P0351, what do you suggest i must do??? change coil and change the di seals??? do both?? or just flash it back to original ?

Please give me your advice.

Thank you!1

Reviving an old thread but I have P0351 P0301 and P0172 codes im boosted and already had coil pack one replaced. Gonna take apart the motor to see what the issue is.

Got the 0351 code a few times, but it seems to go away on it's own within a day or so. It always seems to happen when I'm accelerating hard and in the far upper range on the tach.


For those that have replaced coil #1, has the fix held up? I'd like to take it to the dealer, but the CEL seems to disappear every time I plan to go.

Even if the CEL has gone off the code and when it occurred will be in the memory and accessible by my the dealer.

My CEL came and went a few times with this code and dealer replaced under warranty after checking the diagnostics.

Thanks for reaffirming exactly what I thought to be true. I've moved from where I originally purchased/serviced my car & the new dealer's service rep said that "if the CEL is not on, I won't know what it's for".