I started my 04 base model 6sp with 89K miles this morning BTW it is 100% stock too. I let it warm up about 15mins. the temp outside was around 20. When I went out to get in I noticed it did not sound right. It was kind of sputtering. and the check engine light was flashing. I turned it off, read the codes P0300, and P0302. Cleared the codes and started again. The check engine light started flashing and it was still missing. I had to get to work so I figured as long as I keep the speed low it will be ok. Less than half a mile down the road the check engine light went off and the car smoothed out. Any ideas? I called mazda and they told me to bring it in and the engine is still under warranty. I don't want to take it in unless the engine is bad because I am sure they will bend me over with charges.

 

misfiring
probably time to change plugs/coils. possibly bad gas

 

But is smoothed out really quick. Would bad plugs or coils smooth out?

 

yes its easily possible. The cold weather could make the wiring to the coils brittle and not give enough power to feed the coils properly until you got some real heat from driving for a minute.

Also if you were semi-flooded and didnt know it, once you drive above like 4k rpms' most of the old fuel will be near complete burnt off the plugs and feel better. You do need to change them though, who knows when the last change was and if you semi-flooded or ever flood again, the plugs are no good after that.

 

reset room fuse and see if it comes back.
or you can just pull the plugs and find out yourself

 

you can get spark plugs (2 leading, 2 trailling ) for 80 from fluid, mazmart, bhr. Dont get plugs from an rx7 or anything

You can get the coils at montgomery mazda (onlinemazdaparts.com) for 27.00 each.

I have some taylor racing plug wires if you wanna upgrade those..

 

tonight after work it ran like a top. I guess i will buy new plugs this weekend anyway just in case.