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Old 03-07-2023, 03:24 PM   #1
PLP
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CEL flashing and... gone. P0304 pending

Conditions.
Fully warmed up, after about 20 some miles drive. Driving between stupid speed bumps. I stayed in the 1st gear, pushed to about 5000 rpm and then slowed down.
Somewhere there the CEL started flashing. Engine did not complain. Was smooth and quiet.

Then the CEL, after flashing a few times - less than 5 seconds I would say, stayed off. Engine, again, was smooth and felt powerful. Just normal.

Drove to the destination. Parked. All OK,
Checked codes - Pending P0304.

I cleared the code as I think it is a one time flux due to my weird behaviour.

However, is there anything else I might be missing?
Maybe it is an underlying condition for something bigger?

Tell me if that could lead elsewhere...

Sparks and coils have supposedly been changed about less than 5k miles ago, meaning I put about 3000 while the repair was done 2000 earlier.

So, any warnings or keep going do not worry.

No morning smoke, except occasional puff after longer storage.
No water in oil.
Smooth on cold start and smooth all the way.
Coolant clean and no leaks.

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Old 03-07-2023, 04:29 PM   #2
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Quote:
Originally Posted by PLP View Post
Conditions.
Fully warmed up, after about 20 some miles drive. Driving between stupid speed bumps. I stayed in the 1st gear, pushed to about 5000 rpm and then slowed down.
Somewhere there the CEL started flashing. Engine did not complain. Was smooth and quiet.

Then the CEL, after flashing a few times - less than 5 seconds I would say, stayed off. Engine, again, was smooth and felt powerful. Just normal.

Drove to the destination. Parked. All OK,
Checked codes - Pending P0304.

I cleared the code as I think it is a one time flux due to my weird behaviour.

However, is there anything else I might be missing?
Maybe it is an underlying condition for something bigger?

Tell me if that could lead elsewhere...

Sparks and coils have supposedly been changed about less than 5k miles ago, meaning I put about 3000 while the repair was done 2000 earlier.

So, any warnings or keep going do not worry.

No morning smoke, except occasional puff after longer storage.
No water in oil.
Smooth on cold start and smooth all the way.
Coolant clean and no leaks.
That code is for a misfire on cylinder #4
So you were going over speed bumps when it happened.
Check all your coil packs and make sure they are "snapped" down tight on the spark plugs.
Especially cylinder #4.
Make sure that the wires attached to the coil packs are not loose or damaged.
Clear the codes and drive it as you normally do.
See if the code returns.
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Old 03-07-2023, 05:04 PM   #3
PLP
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Quote:
Originally Posted by blue62 View Post
That code is for a misfire on cylinder #4
So you were going over speed bumps when it happened.
Check all your coil packs and make sure they are "snapped" down tight on the spark plugs.
Especially cylinder #4.
Make sure that the wires attached to the coil packs are not loose or damaged.
Clear the codes and drive it as you normally do.
See if the code returns.
Thanks for the response.

Yes, I checked right away what the code is and I was like - nah, misfire, nothing to worry about. Besides it is pending. but who knows, right?

Sorry, I did not clarify it.
The CEL started flashing when I was approaching the second bump, yet I went through them pretty slowly hence I doubt it was something like a lost connection as the engine experienced more shaking from driving than this little bump. Albeit a bit nasty one.

I am thinking I must have caused the engine to be mad at me for keeping 1st gear for a while at higher rpm... But this is Porsche after all!!

But yeah, I cleared the codes and see what happens next.

My concern is if that could be an early sign of something else.
I know that some cars have some weird warnings and y experience with this brand is still very very very limited.
__________________
Current rides: 2003 Porsche Boxster MT (me), 2019 Bolt LT (me), 2015 Audi Q5 (wife), 2008 VW Rabbit (2.5 inline 5, MT, well, for kid... but you now, it is the 5 straight)

Previous: 2014 Fiat 500e, 2016 KIA Forte5 SX, 2016 Fiat 500X, and some old days: Trabant, Fiat 126p...

Last edited by PLP; 03-07-2023 at 05:06 PM.
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Old 03-07-2023, 05:47 PM   #4
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Quote:
Originally Posted by PLP View Post
Thanks for the response.

Yes, I checked right away what the code is and I was like - nah, misfire, nothing to worry about. Besides it is pending. but who knows, right?

Sorry, I did not clarify it.
The CEL started flashing when I was approaching the second bump, yet I went through them pretty slowly hence I doubt it was something like a lost connection as the engine experienced more shaking from driving than this little bump. Albeit a bit nasty one.

I am thinking I must have caused the engine to be mad at me for keeping 1st gear for a while at higher rpm... But this is Porsche after all!!

But yeah, I cleared the codes and see what happens next.

My concern is if that could be an early sign of something else.
I know that some cars have some weird warnings and y experience with this brand is still very very very limited.
A flashing CEL is considered as something serious.
When the CEL flashes it is telling you that and event is happening that can possibly damage your catalytic converter.
Misfires allow un-burned fuel to enter the catalytic converter. That's not good for them.
Misfires happen for a reason most often coil pack or spark plug related.
Was it wet out when it happened?
Had you driven through any water prior to it happening?
Has any work been done to the spark plug or coil packs recently???
How many miles on the plugs???
Again as I stated above check your coil packs to be sure they are properly seated on the plugs.
You can doubt it was something like a lost connection but you have no way of knowing that if you don't know the cause of the misfire.
Yes a misfire is often times an early sign of something.


Last edited by blue62; 03-08-2023 at 06:59 AM.
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