My computer is showing me the check-engine light. It has flashed a couple of times when it is cold, but that is all. The codes from the computer are P0300-P0304, and P1399. P0300 Means random multiple misfire, and the P0301-04 is indicative of the indivudual cylinders. P0301=cyl 1, P0302=cyl 2, and so on. The only problem is I don't know what the P1399 code means. Does any body know what this code means for an S2000(ap1)? One of the suggestions is that it means a random misfire, but I'm not sure. I don't want to know what it is for another car. I have erased the codes twice, and they keep on coming back. To my knowledge, the performance has not decreased since I've been driving it. When I start the engine after the car has been sitting for a while, it starts with some rattle but evens out after about 30 seconds. It sounds like the oil is getting circulated in those first few seconds. If there is someone who has had this problem, your info would be useful. My car has 102k miles on it (if that helps). Thanks for your help.

 

P1399 goes along with the 0300-0304 codes. If your CEL flashes, you need to fix something.

At the mileage, I'd suggest new spark plugs at the very least. Since you're having all cylinders acting up, less likely to be coilpacks but it can happen.

Usually with those codes, if they're still present after spark plug changes... it winds up being injectors. It's not uncommon for them to have intermittent failure at that mileage and show you those codes.

 

It's a temporary DTC for a pending misfire DTC. Let the engine run longer eventually it will through a P0301-P0304 identifying what cylinder the misfire occurs on.

 

This thread might help:

https://www.s2ki.com/forums/index.php?showtopic=659930

 

Thanks for the thread, Moderator. I'm going to start going through those steps. Thanks again to everyone who posted.

 

I had it flash and give these codes when I was really low on gas. I guess the pump couldn't pick up enough fuel to provide enough pressure for proper spray pattern, adn the cyls were misfiring.

Now I'm turbo, and I still get them once in a while. I guess it's the air/fuel ratio, as I'm at 10.4:1 AFR at a cold start. Oh well.

 

I have had the same issue with my MY00 ap1, and just yesterday i had changed the coil packs on all 4 cylinders, and it cured the problem. First thing i did was to change the spark plugs which seemed to have worked for all of 1hr, but the CEl came back.

Try new coilpacks and see what happens