Flashing check engine

[Jarwulf]

Hi, I was driving my 99 camry LE 4 cylinder when I noticed that the check engine light was flashing and maybe it was my imagination but the engine was running a little rougher. I pulled over and stopped the car for awhile. I added a little oil and then restarted it and felt (or maybe imagined) it running a little rougher for a while until it smoothed out. The check engine light did not come back on. Of course I didn't want to drive enough to make it start flashing again.

If the car was scanned would it still have the information about what caused the flashing? What might it be?

Would ordinary repair people have the scanner or do we have to go to the dealer?

[fenixus]

flashing CEL means the MISFIRE was going on.

there could be PENDING trouble codes in the ECU, but most of them tend to disappear after restarting the car.

any OBD2 scanner can read the stored and pending codes, even the one at autozone or advance auto (free reading service).

[TedL]

As said above, flashing means misfire. Don't think this means totally. Failing to properly fire on a small percentage of revolutions can still be recognized as misfire.

I have to refine Fenixus comment about pending codes. Many codes require two trip failure to set. Clearly, if pending codes were cleared when the car is shut off after the first trip, the ECU would never see it as a second trip with the same error. He's implying that these things often resolve themselves.

[Jarwulf]

I went to autozone and found out they don't do code scans anymore because of some BS law.

I went to another place and found out that apparently no code was stored. They could diagnose it for $$$$ So I'm going to take an educated guess and replace my spark plugs. Do you think that's the best possibility?

The two guys at the shop couldn't agree over which spark plug is the factory type. One said it was laser cut double platinum NGK/Denso which would last 100000miles while cheaper NGK single platinum would last 32000 miles. The other guy said the factory type was single platinum NGK/Denso which would last 60000 miles.

I gambled and ordered the double platinum NGK which is supposedly exactly the same as the Denso.

[fenixus]

ah, right I forgot the People's Republic of California has that BS law, sorry man. glad you scanned it elsewhere.

with intermittent misfire, I would definitely at least check on condition of spark plugs ... or do a minor tune up if it hasn't been done in last 30k miles or 3 years.

That would include:
a) new spark plugs
*I like OE style plugs like Denso Double Platinum PK20TR11 or NGK Laser Platinum BKR6EKPB-11), but for 5s-fe you can safely go with NGK Iridum-IX BKR6EIX-11 since replacing them every 30k miles is very easy.
b) new spark plug wireset NGK TE58
c) new air filter (any paper insert will do, good idea is WIX/NAPA Gold, but even FRAM or Purolator Classic will do on this one)
d) new OEM fuel filter (or at least WIX from NAPA Gold series) if you have a set of flare nut and open end wrenches (or bring it to your mechanic), OEM ones come with bracket for easy installation, aftermarket ones don't (extra struggle step involved)
e) new drive belts, e.g. Dayco or Gates if they haven't been changed for a while (not that it matters for a misfire problem)

if there's no rush I would order those things off internet, e.g. rockauto.com or amazon.com, if you want to do this quick then you will be shopping NAPA or Autozone at their killer pricing as there is no Advance Auto Parts in California unfortunately (they have awesome discounts online up to 41% off with local pickup option).

I also like replacing cheap OEM stuff like fuel tank gas cap, radiator cap and PCV valve+grommet, both from the dealer online, around $15 each of the three.