Hello,
I have a 2000 civic. The CEL came on, so I brought it to Autozone for the free error code check. They came back with P0301-P0304 - misfire detected on all cylinders.
The car is running ok though. It seems to idle a little low at stops, but the power seems good, and it doesn't seem to drive rough when accelerating.

Any ideas? Since it's running ok, does that help narrow down the possible cause? Or does that make it even harder to diagnose?
I'm not a "car guy" really, so can't do too much myself. I'm just hoping to get an idea of what I might be looking at to fix this.

Any input is greatly appreciated!

 

Last tuneup?

 

To be honest, I'm not exactly sure. I've only owned it for a couple months. It has 111,000 miles. The previous owner said they receiently did a tune up, but I don't have receipts or anything to prove it.
Seems to be running fine. And I just ran to the store - CEL was on when I drove there. When I came out and got in the car, it didn't come on on my way home.
Should I just wait to see if it comes back on?
Probably worth doing a tune up anyway?
I appreciate any advice!

 

I haven't had a chance to test the car today yet. We got a big snowstorm last night.
Once we're plowed out, I'll go take it for a ride to see if the CEL is back on, and if it's still running ok.
Could something throw the P0301-P0304 errors, but then "fix itself"?

 

could start with spark plugs

 

Possible bad gas? Intake manifold leak? Clear the codes and see if they come back.

 

start with plugs. replace with ngk.

 

Replace the spark plugs and wires, the distributor cap and rotor, and the fuel filter.

If the problem continues, then test the coil and ICM in the distributor (see FAQs sticky).