code P0300 random/mutiple cylinder misfire?

M

montpas

Member

:

Mazda Protege5

• Apr 30, 2011

• #1

what to do? spark plugs are new. do i need new coilpacks or wires? help me!

 

M

MasonMetcalfe

Member

:

2002 Mazda Protege 5 Dark Blue

• Apr 30, 2011

• #2

quite possibly. if its happening when the engine is hot look into cleaning your EGR.

 

C

CheeseHelmet

Member

• Apr 30, 2011

• #3

If your car doesn't idle like s*** then yes, it's probably the coilpacks (while you're at it change the wires too). If it doesn't idle well then your EGR valve might be malfunctioning.

 

B

bigpturgeon

Member

Contributor

:

Mazda Protege 5

• Apr 30, 2011

• #4

I agree ^

 

G

gino

Member

:

'03 P5, '14 iTouring hatch, '04 Honda S2K

• May 7, 2011

• #5

I let an on-again, off-again misfire go for a week, knowing in my heart of hearts it
had to be a coil pack on 3/4. I ended up replacing not only the pack (tossed in a
set of plug wires as I'd reached 155K), but a 6-month old cat, as well.

The unburned fuel from the going through the cat burned the biscuits to cinders.

Expensive lesson.

 

S

spotthedogg

Member

:

2002 Mazda Pro5

• May 30, 2011

• #6

Mine was very rough all the time, started 2 days ago. I pulled the plugs and they looked OK but dropped in some fresh Denso anyway. I pulled the EGR and it was stock open. I cleaned it with brake fluid, worked the plunger in and out several times and it started snapping right back the way it should. I DID NOT DISASSEMBLE THE EGR, I just dumped some fresh brake fluid in the ports and worked it in and dumped it out. 25 minute job. Car runs perfectly now $0

 

I

iJay

Member

:

Mazda, Protege 5

• May 30, 2011

• #7

Had this code, changed coils, plugs and cleaned the EGR, while brake CLEANER works I am not sure about brake fluid. I also used a lil dremel tool to bring the inside of it back to a bit of a shine and the pluger was able to move freely

 

S

spotthedogg

Member

:

2002 Mazda Pro5

• May 31, 2011

• #8

Brake fluid is nasty stuff and it's leaves a high temp lubricant. I think it'll work well.

 

S

spotthedogg

Member

:

2002 Mazda Pro5

• Apr 22, 2012

• #9

Still going great!

 

T

tweety2300

Member

:

2001 mazda protege mp3

• Apr 22, 2012

• #10

My car idled like s*** when the coil packs died...

 

B

bdruff

Member

:

mazda protege5

• Nov 11, 2014

• #11

getting a p0300 code. Other symptom: Around 20 mpg (Every time) there is a rough stutter. Goes away then runs great. Plugs changed... haven't done the coil packs yet. Any ideas? I'll keep reading here

 

T

The_big_dill

• Nov 11, 2014

• #12

bdruff said:

getting a p0300 code. Other symptom: Around 20 mpg (Every time) there is a rough stutter. Goes away then runs great. Plugs changed... haven't done the coil packs yet. Any ideas? I'll keep reading here

Click to expand...

Read again.

The causes are either:

- Coil packs
- EGR

 

P

pcb

The Diagram Dude

:

2002 MP5

• Nov 13, 2014

• #13

There's lots of causes for a P0300 code.

Your specific symptoms may rule out some of them,...

 

L

L4junky

Member

• Dec 1, 2014

• #14

Somewhat new to this forum, I have a similar problem with my '03 P5. Intermittent low idle (as low as 200 RPM) and random P0300. Cleaned EGR valve 11/23, no change in idle and got another P0300 this morning. Using Torque Pro for Android, I can pull Freeze Frame data but only short term fuel trim is out of range @ 19%. I know coil packs are recommended at this point but I'm also suspicious of a crank or cam position sensor, any thoughts?

Sent from my LG-L38C using Tapatalk 2

 

T

The_big_dill

• Dec 1, 2014

• #15

Don't be suspicious of anything else until you tries the popular solutions... Unless you like chasing your tail with problems. Change coil packs, clean egr, then move to less common fixes.

 

M

MaxRX7

Member

• Dec 17, 2014

• #16

new coil packs fixed the problem and the P0300 code went away for good.