ECU code 0170?

I have a 0170 code on my car it says Fuel Trim Back 1. WTF does that mean.lol


PCE!

I dnt know why i said ECU code lol its the CEL code sorry about that,

That is a fuel trim malfunction, you are running rich or lean.
Check spark plugs, o2 sensor.

Most likely o2 sensor. That code just means the ECU is at the end of its range trying to adjust your closed loop AFR to stoich.