Today on the way home I noticed my Check Engine light was on. I don't know if had JUST come on, I simply noticed it on as a new thing in my life.


It scared the crap out of me so I pulled over immediately and opened the hood, wiggled wires, checked oil, etc. Everything seemed fine, no strange smells.

I restarted the car.

-Car seemed to be running normally with smooth idle; no ticking, missing, strange noises, roughness or anything

I drove to Kragen cautiously and bought an OBDII code reader.

It showed four codes, all "misfire" related:

P1399 (Honda specific) Random/multiple cylinder misfire detected
P0300 (generic) Random misfire detected
P0301 (generic) Cylinder 1 misfire detected
P0302 (generic) Cylinder 2 misfire detected

This is an early MY2000 S2000 with about 42000 miles and no significant problems ever. I have had all the TSBs done, including the spark plug recall done a few years ago. In 6.5 years I have never, ever previously seen the CEL until today.

It is kind of an ugly drizzly day so I was driving conservatively, absolutely no overrevs or even VTEC today.

The only notable things I can think of are:

1) Weather today changed with a drop of around 20 degrees and some light rain, nowhere near enough rain for any kind of water-related engine problems and I didn't hit any puddles worth mentioning. I have an all stock engine, air intake, etc.

2) My OEM battery is on its last legs. I keep it on a trickle charger at home, but the battery is over six years old and I can tell it runs down quickly if I listen to the radio, etc.

3) I had a near collision this morning requiring a full-on ABS-skidding brake to a complete stop on dry pavement (an idiot pulled out of a side street and stopped right in front of me.) The engine did not stall as I had both feet in and there was no contact with anything. I don't know if it could be related, but nothing else notable seems to be happening.

So, what should I do, if anything? What should I look at? Is the car safe to drive?

Should I reset the CEL with my nifty new OBDII reader and just see what happens?

I know there are a lot of great mechanical minds in here with much S2000 knowledge, so thanks in advance for any advice!

-John

 

Those are serious codes.. I would think you would feel/notice them.

 

I honestly didn't, but the roads around here are crap so maybe they got lost in the bumps. And I don't know if those codes mean there was continuous misfiring or if one and two missed once and that caused all four codes...

I was really surprised that there were FOUR codes.

 

Come to think of it, what is it that I would have noticed?

I guess that's part of my confusion. I don't know how bad this is, how serious of a problem would have caused it, what would have caused it ("Cylinders misfired???) It's just a completely new thing to me after a lot of years of driving this car.

 

MANY things can cause a misfire:

-Valve clearence
-spark plugs, faulty coils
-dirty injectors
-low compression
-low fuel pressure
-poor fuel quality
-intake manifold leak (unlikely on the s2k)
-loose spark plugs (improply performed recall)

 

First, I assume you are using premium gas and not regular. I have seen regular cause random misfires before.

secondly, if you are comfortable with it, take the valve cover off and the coil packs off, and pull your spark plugs. check them to make sure they look normal. if any of them look "different" you can post back here and let us know.

were the spark plugs loose? do you see oil on them anywhere? when you put the spark plugs back in, torque them to 18 lb/ft.

this actually happened to another member here very recently, and billman provided similar advice as well. that other member seemed to have a much worser issue, but none the less, checking spark plugs is a good place to start.


if you are not comfortable doing the above, or dont know how, then you can clear the code, and if it returns, time to visit the dealership.

 

50K miles is a lot for a AP1 valvetrain. Start with the basis others suggested: spark plugs, coil packs, animal sacrifice, valve clearance check, etc. Good luck.

 

would that be large or small animal?

 

I would think opossum or armadillo in this instance. They seem to lend themselves to sacrifice quite frequently.