Evo owners come on in

NYSpeed Automotive
1

I have an 03 evo, and I was wondering if any of you guys have had a run in with the P0300 misfire? basically, the engine senses some vibrations and mistaken s it for knock, putting my car in limp mode until I let off of the throttle. This only happens here and there and it happens with my tune and happened before my tune.

Anyone had this problem? Any suggestions? I am going to getting different plugs to start, seeing how I have the iridiums that your not suppose to gap…

Any input would help, thanks guys

2

whats done to your car? change out the plugs

3

Mod List?
Tuned by?
Miles on it?
Fuel?

4

I had a similar problem, I changed out my plugs with OEM NGK and it would fix it till my running pig rich would ruin them again…

5

so if im totally wrong i can take it but all the googleing ive done come up with a P0300 misfire as being a cylinder misfire. am i right or wrong?

and if im right heres what theyve got for ideas:
* Faulty spark plugs or wires
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector(s)
* Burned exhaust valve
* Faulty catalytic converter(s)
* Stuck/blocked EGR valve / passages
* Faulty camshaft position sensor
* Defective computer

6

P0300 is a misfire code and is set when the engine misfires.

I would check your ignition related components first and go from there, check the wires for burn marks and check the coils for the same. I would run NGK copper plugs in your car but that’s just me. Gap to .028.

Good luck. :slight_smile:

7

You are right, but that is like saying 1 = 1, heh. He already posted up that it thinks it has a misfire. :eekdance:

8

mods are:
-3in turboback
-cone filter
-mbc set at 22lbs
-walbro 255

49k on the car, im thinking its those plugs, thanks for the help so far guys, keep it coming

9

stock clutch?

10

i got this code on my car also
changed the plugs made no difference for code but car felt better
for me its the clutch i have which is chattery
im awaiting a new tune to eliminate this code
best thing id do for you is to change the plugs and check the wires

11

yes stock clutch, she holds good, kinda has a little slip going from 2nd to 3rd past 7000rpms…

yeah im going for the plugs, wires check fine, no cel though but the guys on evom are still pointing to that misfire code

12

id check the plugs and wires like stated above. Change if needed…if you still geta misfire with plugs…maybe check to see if you have a weak spark