HELP: Check Engine Light

For some reason today my check engine light came on. we've had a couple inches of rain and it came on right after driving through a puddle. I wasnt going extremely fast and the water wasnt even high enough to reach the rim on my tires. Its a 2000 tacoma V6 SR5. Any ideas why this happened?

 

What are the codes?

 

I don't have a code reader. I didnt think going through a puddle could cause this but..... Weirder things have happend to me.
I am hoping something got wet that shoulnt have and the problem is not perminant and the light goes away when it dries.

 

You can go to Autozone and have the code read for you.

 

First time I had a check engine light was when it was raining. Code turns out to be cylinder misfire code. Dielectric grease to the boots and code was gone. Find out what your code is.

 

Thanks, getting it checked on the way home and i will post the code when i get it (if they cant tell me what it means).

 

They should be able to tell you what the codes mean. I guess the misfire code is common when raining, at least from what I saw when I searched.
P0304 = Cyl 4 misfire. Last number indicate which cylinder.

 

Below is what the print out from autozone said.
"Troubleshooting P0420
Catalyst system efficiency below threshold - bank 1
Probable cause
- Air leak in exhaust before rear HO2S (Heated oxygen sensor) Bank 1
- AF sensor error
- Fuel system fault
- Faulty catalytic converter"

So maybe water got in the HO2 sensor. That's what I'm hoping.
I have never needed to use the code reader so i gues my next steps are to check each thing listed? Will the check engine light automatically go off when i find and fix the problem?

 

Passing through water probably caused some to get into a connector. Look at the oxygen sensors and pull the connectors. See if there is any water on the inside. If every one of them is dry then you may need a scan tool to look at data, or take it to a shop that can look at it. If you fix the problem you will still need to clear the code yourself. You can either do the common "disconnect the battery" method, but if you are like me, and hate having to reset the clock and radio presets, then you could take it back to autozone and ask them to clear the code for you.

 

I read from another forum thread with a similar issue to dissconect the batt and if it is still a problem the CEL will come back on. It hasnt for about 30 miles (2 days) and everything is drying up around here so I think water was the cause. I am still going to double check all my sensors this weekend when I change the oil and seafoam.

 

My local autoznes will no longer clear codes. I was told they didn't want the liability. (although if I talk to the right guy he will do it usually)