Hello, I have a 2017 Kia Optima LX 2.4 L that has a Long Term Fuel Trim of over 10%. I want to know what the procedures going (simple --> complicated) to what may be causing the % to be so high over the long term. What are the simple fixes I can do first before I start doing more complicated/expensive things.
Thank you to whoever is kind enough to answer.
Since the computer is adding fuel that indicates a lean condition. Probably the simplest thing to check for would be vacuum leaks.
Thank you for the response, I don't hear a vacuum leak anywhere when I put my head close to any of the hoses.
Is there something else that could make it be so high?
I don't hear a vacuum leak anywhere when I put my head close to any of the hoses.
That is not a very definitive test even for hoses, and bad gaskets or cracked intake manifold can also cause a vacuum leak.
https://www.youtube.com/watch?v=4ktw1X4W_-k
Thank you, I will try this and see how it goes.