Error code P0300 ( Random Miss Fire )

[mr.valov]

Hi Im driving 2002 Mazda Protege5
I was away for about 4 months and
the car was sitting in the garage at
that time. When I came back, my
battery was fully death and luckily
i got it back alive after 2 days recharging.
But then the problems started. On the second
day my car star shaking on a red light loosing power
then the check engine light start flashing and I barely
made it to the other side of the traffic light and I stooped.
The check engine light stopped flashing and it came solid. I
Went home and I connected it to my OBD tool and the
error code came P0300. I star browsing about that problem
but no fix so far. I have changed the fire plugs with brand new
Bosch Platinum and I cleaned the error code. On the next day
the same problem happened and then the most weird thing started.
Every time after miss firing my check engine light comes on, but on
the next day the light just disappear itself without my help ... 5 times so far this thing
happened to me. What is it ?
I love my mazda so much and I need a little help to figure it out what is the problem.

Thank you for your help in advance !

 

[StealthWyvern]

Change your coil packs, if that doesnt work change the wires. Also bosh plugs are crap on these cars. The cars seem to prefer the NGK or NKG or whatever they are called.

 

[localkineguy]

You're check engine light will turn itself off if the problem doesn't persist after some number of driving cycles. I think it's three, but somebody can feel free to correct me. It'll turn back on when the problem resurfaces. I agree with the other poster, check your coil packs and wires.

 

[StealthWyvern]

You're check engine light will turn itself off if the problem doesn't persist after some number of driving cycles. I think it's three, but somebody can feel free to correct me. It'll turn back on when the problem resurfaces. I agree with the other poster, check your coil packs and wires.

You are corerct. Also they will also be in pending status and never trip the light after 3 instances of it.

 

[Jordysoso]

Swap plugs with NGK v power or g power. Might as well do a coil pack and wire swap. Go NGK wires and as for coils, I used BWD. Let us know if it works or not

 

[mr.valov]

Ok so far, I have changed the original wires with New NGK wires, but no luck so far.
After I installed the new wires, the car started normally, I went to work ( I was there for 5 hours)
and when I tried to start the engine... and it didn't work... I opened the hood removed the wires placed
them back again, and the car started but seriously shaking with a check engine light flashing. Then I shut it down
and turn it back on again and after a few times doing that the engine was working fine. I just don't know what to
do next should i change the Ignition Coils ? I have found Beck Arnley ignition coils on a good price... should I buy them?

 

[hornsfan10609]

I have had good luck with the duralast coils from autozone, they are about $26.

 

[mr.valov]

Did you have the same problem tho ? Why did you replace yours ?

 

[bigpturgeon]

Its your coil packs just change them.

 

[DarkAngel]

Oh man bringing this back from the past......

For anyone wanting to trouble shoot, while the motor is on, remove the grey plug from the coil and see if it makes a difference. I had a coil pack go bad yesterday. A quick way to check is removing one of the two grey plugs from the coil pack at a time. If the engine stalls, then that coil pack is ok. If there is no change, then that coil pack is toast.

Symptom:

Engine/Car ran like it had no power, engine shook like crazy, A/C really drained the power as well due to powering the compressor. It threw two codes which were both misfire codes.

Replaced the bad coil with a back up I had and all is well for now. Will be buying two new ones really soon.

 

[Carl]

Bringing this thread back from the past, again...

When I had a CEL error code P0300 ( Random Miss Fire ) at ~90,000 miles I eventually changed the 2 coil packs & 2 ignition wires for $100 from Autozone.

The CEL went away.

The MP5 ran like a champ.