P0303 then P0300 Codes

[BREADwagon]

Hello!

About 11 weeks ago my car's CEL lit up. I brought it to the dealer and they said it was a P0303 code (Cyl. 3 misfire). They swapped the coil and sparkplug on cyl 3 only. Now, 3300 miles and 11 weeks later my CEL lit up on the commute home. I had bought a elmscan usb, so I checked the code. It showed that the P0300 (random misfire) was thrown 30 miles ago (during my commute which made sense).

I've searched the board for P0300 (and P0301 - 4), and most of the responses are check the plugs/coils. Since they changed that coil already, I wonder if there is some other problem. Had anyone here experienced the same issue?

I DON'T want to bring it to the dealer, have to wait for them to order the coils, and just swap them blindly. I'm thinking there is a deeper problem than just coils/sparkplugs.

(FYI Gas cannot be bad because I do not hear any ping, and I'm already half through the tank so the mis-fire would have happened earlier if it was the gas.)

 

[DreSEL]

Something similar happened to a friend. The code was for cylinder 3 misfire. The car was trembling and sounded like it was running on 3 cylinders. The problem went away on its own but it came back a few weeks later. He took it to the dealership, and they reflashed the computer. That solved the problem. The ignition system was fine, it was the ECU itself.

 

[BREADwagon]

Interesting. Do you know the details about the flash? Was it a new revision? OR was it the same flash, but the original somehow became corrupted?

 

[typeshluder]

I actually got a P0300 code a few weeks ago. I have the Hypertech and was running 91 octane for that tank, so I figured that's what it was. I cleared it and it hasn't come back, but I've been running 93 octane.(dunno)

 

[79535]

I am still suffering from a P0302. Different cylinder, I realize. I replaced the coil and plug and am still having the issue. The harness appears to be is great shape.

The repeated cylinder 2 misfire actually killed my primary O2 sensor from fuel saturation.

The problem still is not resolved and will be going back to Mazda for them to investigate this time.

I will update you if I find a definitive answer for my problem.

 

[MS3 GT]

my car was showing p2187 back then now its on for p0301, the car ran fine, my guess will be mods that i had done to the car. a tune would solved the problem。

 

[mcb]

p2187 is, not alway but often, related with a leak. My car
throwed p2187 and p2177 last week. I found a leak in my bpv installation. Now its fixed.

I had a p300 when the car was brand new(less than 500km) they did a special procedure i dont have the exact details but it involved revving the engine to 4k rpm for some time and other rev after. Anyone know what i'm talking about?

I will check in the shop manual if the procedure is explaned.

edit:

see the manual: http://www.mazdas247.com/forum/showthread.php?t=123745704