Running too lean?

[gfunkfb09]

My check engine light came on and I had Advanced Auto Parts scan for the code.

It came back as my yukon running too lean, and it was giving an error on the 2nd knock sensor.

Has anyone else run into this problem?

They told me it could be a bad knock sensor, bad MAF or a clogged fuel filter.
What do ya'll think?

I cleaned the MAF today and that didn't solve the problem, I got the same error last week and when I put more gas in the check engine light went off and today it came back on. And around Thanksgiving my fuel pump went out and I got a new one of those.

Thanks guys!

 

[blueflamed03]

Is yours FlexFuel? Or regular? If so, changing fuel filter is easy....and may be a good change anyway.

 

[gfunkfb09]

Its FLEX

 

[blueflamed03]

a little more in detail, search Youtube, but i'd get it changed.

 

[gfunkfb09]

I will try that first then since its the cheapest.

 

[gfunkfb09]

I bought a new filter today and am going to tackle the task of changing it later. Are there any tips and tricks to getting it changed? I haven't been able to find much about it else where.

 

[07Burb]

I know the one's for regular fuel are really easy and are inline right along the driver's side frame rail but I'm not sure how the Flex Fuel filters may be set up differently. Do you have an idea of where your fuel filter is located and a pic of what it looks like?

 

[gfunkfb09]

I haven't looked yet, im assuming thats where it is though.

What tools do I need?

Do I need to depressurize the fuel system? if I do, how?

 

[gfunkfb09]

I'm having the hardest time getting that filter off! How do you get the clamp end off?

 

[Mr.Martin]

Flex fuel has a plastic clip thing on one end. There is a little tool made to remove it but I just used a flat head screw driver and patience.

This is what the right tool looks like

http://www.sjdiscounttools.com/ast8022.html