P0174 code
 

Hello everyone!

I have a 2008 Jeep Grand Cherokee limited with the 5.7L hemi. I love this thing! It has it all! However, I have recently noticed my check engine light has come on with a code of P0174 and my scan tool says my "system is too lean" and I also recently just installed a high flow car assembly and a cat back exhaust system on my jeep. It sounds amazing but my tail pipe is black as hell. I know that isn't normal so I took my jeep back to the guy who installed it and he said that that I am burning a lot more fuel than normal now. He suggested that I needed to get an "air fuel ratio meter" for 2:1? I believe he means I need a new oxygen sensor and he said that he knew what he meant and not an oxygen sensor. With all that being said, does anyone have any advice or suggestions? I got my exhaust a few weeks ago and just yesterday my check engine like went off. It had been on the past few weeks. Thank you!!!