2003 Corolla Le Misfire - Help! - Toyota Corolla, Chevy Prizm (1998-2008)

Hi everybody,

My car is 2003 Corolla LE. The engine runs pretty smoothly. Today, the check engine light was illuminated. When I pulled the code, it tells me: cylinder #1, #2, #3, #4 misfire. This is the 3rd time check engine light was illuminated.

The first time the light illuminated is around exact one year ago in Dec 2008. The code was Cylinder #1 misfire. What i did is that I changed all the spark plugs and unfortunately I did not gap the plugs properly. So two weeks later the light was illuminated again (2nd time). The code was Cylinder #1 and #3 misfire. Following this, I changed all the plugs again using iridium plugs recommended by Toyota dealer and had the gap checked. Meanwhile I added some fuel injector cleaner (Lucas product). The problem was gone.

Exactly one year later, today, the check engine light was on again. Currently I have been using the same injector cleaner (lucas) since 2 months when winter started.

What I remembered is that all of these engine misfire happened right after a sudden drop of the temperature, e.g. last night from 0 to -12 (Celsius) - I live in Montreal. The first two time, it was like this time, i mean, I left the car parking outside more than 5 or 6 hours while the temperature dropped suddenly. The check engine light was illuminated right after a engine start up (around 30 second after the engine started) in all these three times.

Has anybody experienced the same problem? Does anybody know what is happening. Please help!

Any suggestions are appreciated! Thank you in advance for replying!

Hi All,

Since last time the check engine light was illuminated (Dec 16 2009 - I immediately erased the code after scanning), today the light was illuminated again. This time I did not pull out the code and decided not to drive my car until the problem is fixed (made an appointment with Toyota dealership on Jan 2010 - because the holiday season, there is no more appointment available before that).

today's date - Dec 22 2009

Hi all,

I want to report what happened on my 2003 Corolla LE today. What happened today is the check engine light turned off by itself when I started the engine. Since the CEL was illuminated four days before, I hadn't driven it until this afternoon. (Please refer to the my previous report in this thread.)

It is very strange to me, since if the engine was misfiring, I guess the light should not go off by itself.

What I could figure out is maybe the Electronic Control Unit (ECU) was malfunctioned when it was frozen (the check engine light was illuminated every time there was a sudden drop in temperature, and the temperature was at least -10 deg Celsius).

so I have two questions,

1) since the CEL is off now, Can I drive my car without having it inspected by a mechanic?

2) what could be the reason causing this problem?

Please feel free to share your opinion, any suggestion is appreciated!

Hi All,

Just to report what happened, the CEL came on again last night.

Does it normal that the engine behaved differently every time when it warms itself right after a cold start - i mean "differently" is REVs changed a lot every time. After warming up, idle speed remains constant and pretty stable.

Does it sound familiar to anybody?

I know little about cars per se, however the drop in temperature may have an affect on the strength of the charge to the spark plug. Does the cold weaken the voltage? Is it a coil issue? Like I said, I don't know a lot, but the cold seems to play a major part in your delimma.

You know, I have come to the conclusion that Toyota suffers because of its American dealers. I won't go back to my dealer; I go to one several miles further north, in another state. Take your car to a better shop.

Possible that the extremely low temps you are seeing is causing the coil packs to fail or the injectors are excessively clogged. Possible the low temps are causing the injectors to not work properly, this is further complicated with additives that help prevent any moisture in the gasoline from freezing - as those tend to require a slightly richer air/fuel mix than what the ECM is programmed for.

Could have something completely separate from the fuel and spark that might be causing this. A leak in the intake manifold would also cause a misfire - excessively leaning one or more of the intake charges. Excessive carbon deposits can also cause a misfire - depending on the mileage you have on the engine and the driving conditions (aside from temperature) - might need to decarbon the top end of the engine.

Since the car seems to run well once it reaches operating temp - I would guess that it is an initially fouled injector(s), weak coil pack(s), and/or leak in the composite intake manifold. Most additive that you add to the tank do very little for cleaning, some of them do work to a certain degree, but if you have significant carbon buildup - will take a shop to clean that up (add cleaning agent directly to fuel rail).

Poor chassis grounds (leasds to electrical noise) can also cause misfiring. Since this is most apparent when the car is cold, could indicate that a common chassis ground is make poor contact. If you have a multimeter handy - you can verify if the grounds are good or not (measure voltage potential at each point). Solution there is as simple as cleaning the contact and tightening the fastener - might want to hit afterwards with a little grease as well, to keep corrosion / moisture in check.