P0300 2003 Protege5

A

Aerobat66

Member

:

2003 Protege5

• Dec 27, 2016

• #1

I just replaced a bunch of parts in my daughters car, and am now getting a P0300 with rough running. That is a multiple cylinder misfire code. I just replaced all 4 spark plugs with NGK 3440 BKR5EP11, and both plug wires and both coil-on-plugs with NGK, and then the misfire began.

For further reference (just in case), I also replaced the air filter, fuel filter, valve cover gasket, PCV valve and grommet. A few weeks ago, I also replaced the EGR valve.

Could it possibly be the double platinum plugs? Or should I look elsewhere to solve the problem? Like the coils themselves?

 

Last edited: Dec 27, 2016

J

Jfunk

Member

:

02 protege5 5spd- wrecked rip. 03 protege5 5spd (parts)

• Dec 27, 2016

• #2

I had a similar problem a couple weeks ago and it turned out to be a timing belt tensioner and it was completely coincidence that i had the valve cover off the night before. I doubt this would be the issue but you can read this thread if you want https://www.mazdas247.com/forum/showthread.php?123858498-running-BAD-at-about-300rpm-PLEASE-HELP

 

J

Jfunk

Member

:

02 protege5 5spd- wrecked rip. 03 protege5 5spd (parts)

• Dec 27, 2016

• #3

Jfunk said:

I had a similar problem a couple weeks ago and it turned out to be a timing belt tensioner and it was completely coincidence that i had the valve cover off the night before. I doubt this would be the issue but you can read this thread if you want https://www.mazdas247.com/forum/showthread.php?123858498-running-BAD-at-about-300rpm-PLEASE-HELP

Click to expand...

Also forgot to mention didn't have any engine codes when the engine was running rough. It did have the symptoms of a misfire

 

P

pcb

The Diagram Dude

:

2002 MP5

• Dec 28, 2016

• #4

If you replaced your coils, try putting your old ones back on and see of the code goes away.

Coils on our cars area real source of aggravation.

 

i12drivemyMP5

<<<<<<< >>>>>>>

Contributor

:

-- 03 P5 / 23 CX-5 --

• Dec 28, 2016

• #5

Maybe it's the stupid laser platinum plugs (BKR5EP-11) you put in it? Our cars do not need or like that crap. Just use the regular copper plugs (BKR5E-11) or the long reach coppers from the 2000 1.6L (ZFR5F-11) and save yourself some headache.

 

P

pcb

The Diagram Dude

:

2002 MP5

• Dec 28, 2016

• #6

Regular copper plugs work best for our car except you have to gap them occasionally and they need to be replaced more often.