About 400 miles ago, my '96 3.8 threw a P0300 code while driving home from work. The MIL flashed for probably about a minute, then went constant. I didn't feel anything problematic from the car itself, but took the nearest exit just to be sure. Popped the hood, and the engine was purring along as though nothing was wrong. I turned off the car and released pressure from the gas cap (I've heard that sort of thing can trigger an MIL). I then checked and erased the code, and it hasn't come back since. Car still runs fine, and everything checks out visually under the hood (day and night).

What's the chance that this was a fluke?

On the one hand, I'm tempted to replace all sorts of things just to be sure it doesn't happen a second time (plugs and wires are at the top of the list) but on the other, I'm thinking "If it aint broke, don't fix it". I'd really like to have the extra money in case something like the alternator wears out on me (from what I can tell, It's the original from '96.)

 

If it was flashing, that indicates a mis-fire. If it were just the gas cap, I would expect a solid SES.

I had the same thing happen a few months ago. Had a flashing SES, scanned it and found a "Random/Multiple Misfire". Cleared it and it never came back.

 

a flashing SES light mean iminat catalyst/engine damage will occure soon if not fixed. I'd say have it scaned and look at the misfire history and see if that brings you up anything. Or like Nathan said clear it and see if it comes back.

 

Sounds almost exactly like what happened to me. A code P0300 is a random multiple misfire. I scanned it myself. I also erased it, and it hasn't come back.

What's strange is that it was blinking for a moment before going solid. There was only one code, the P0300 indicating the random multiple misfire. Since then, there have been no SES codes, and no pending codes. My OBDII scanner has an option for running a kind of "inspection" test, and that also comes up clean.

I still wonder what it could have been... a bubble in a fuel line? Too much air passing through the cai when the weather pressure and temp were just right? Anyway, I'm not going to sweat it unless it comes back.