Check Engine Light problem - Toyota Nation Forum : Toyota Car and Truck Forums

Sudhir · 08-02-2007, 11:03 AM

The first time I got CEL I got two error codes P0300 and P0171 repeated twice. The mechanic erased them saying we will see if they come back!! Then my car starting hesitating. Then the CEL showed up again with the same codes twice. This time I was out of town, the Advanced Auto guy told me to get the Spark Plugs and the wires replaced, and he erased them. Then the CEL showed up with only code P0171.
I have been to several mechanics, everyone with a different opinion.
Can someone help me please?

Crowbar911 · 08-02-2007, 11:06 AM

What year corolla?

Sudhir · 08-02-2007, 11:10 AM

2000 Corolla LE

stubborn1 · 08-02-2007, 09:23 PM

The P0171 is from the oxygen sensor detecting a lean condition. The P0300 is a random misfire code. Usually, the P030X codes are a result of a different problem if you have more than one trouble code. Work on the P0171 first.

I've heard of people having issues with dirty MAF sensors throwing the P0171. Try to clean your MAF sensor and see what happens. It's easy to do and won't cost you much. Do a search on "clean MAF". I'm sure someone has written it up by now.

Sudhir · 08-12-2007, 11:34 AM

I got the MAF cleaned!! The car started running better. But ALAS!! the light came back.
Could this be due to the fact that I have a K&N Air filter?