05 2500hd 6.0l throttle body

[Tjcharnley]

Cleaned my throttle body at around 190k, now I get a weird whistle at a certain rpm and it keeps throwing a code for it running to lean. I did not change the gasket. My thoughts were it is sucking extra air in the throttle body. Also has. K&n cold air intake. Any ideas?

[dewfpo]

It does sound like an air leak. Spray throttle body cleaner (short, targeted squirts) around the throttle body and all hose connections when it is idling and see if the idle speed goes up. Then pinpoint where it's getting in.

 

DEWFPO