Codes involving air and fuel mixture?

VIDEOMAN26

MEMBER
2007 TOYOTA COROLLA
1.8L
4 CYL
2WD
AUTOMATIC
118,000 MILES

My Toyota has come up with codes involving air and fuel mixture. I have replaced MAF sensor, fuel injectors, pcv valve and hose. Upper and lower oxygen sensors, and catalytic converter pipe that runs to the manifold. The car runs good and has power. Also when driving the headlights dim once and a while and they also dim when hitting a power window button. I am at my wits end. I need help. Can you help?

Thursday, November 6th, 2014 AT 6:38 AM

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

Are you getting rich or lean mixture codes?
The mixture issue can be caused by various components, it can also be triggered by faulty wiring to a given component. So even if you were to replace that part it will not fix the issue as the problem will still exist.

Let me know what are those code numbers. This can help us diagnose the issue and find a solution.

As for the diming of headlights, it can be due to low alternator output or faulty wiring.
Test the alternator to see if it is producing the right amount of output to the battery.

Here is a helpful guide of how to test the alternator:

https://youtu.be/Z-p4dMJUpUw

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Please let me know of any questions.
Thank you.

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