tyne

I have a 2000 Civic EX with a manual transmission and 123k miles. I haven't had many problems with this car but I went to start it last night and it idled VERY rough and the check engine light came on and flashed so I left it be for the night. I went out this morning and checked all the fluid levels and it was VERY low on coolant but all other levels were fine. I filled it and restarted it and it was still rough but slightly better. I drove it down to autozone and after a bit of a rough start getting going (in the parking lot) it kicked right back to it's normal self and drives and idles better than ever. The light went from flashing to steady. I had autozone check the codes and here's what came back.

P0300 (random misfires)
Probable causes 1. Ignition system fault-spark plus, ignition wires, coil
2. Vacuum leak
3. Injector fault
4. High or low fuel pressure

P0301 (Cylinder misfire detected - Cylinder 1) Same probable causes

P0303 (Cylinder misfire detected - Cylinder 3) Same probable causes

P1399 - I don't know what this one was about since when the guy pulled it, it only talked about causes in Chryslers and Volkswagens.

I drove it about 12 miles and as I mentioned, it's running like a champ. The guy said I probably need a tune up. It's been about 1.5 years since the last one at which point the timing belt was also changed. How often are tune ups needed? Does what he told me seem probable? Should I disconnect the battery for a bit and see if it resets the light? Any thoughts on if it's safe to continue driving for the time being? I appreciate any help on this.

z6hatchboy

i didnt see the 1399 on the list for those codes but. Have you tried a normal tune up with plugs, wires, cap rotor and maybe some fuel treatment?

tyne

The plugs, plug wires, and distributor cap were all replaced in April 07 (the rotor wasn't). I don't do too much driving and even less lately due to buying a bike but is it possible they need to be replaced again? Will the light automatically go off when the problem is fixed or do you have to have it reset?