Hey guys, problem here. my 01 F150 5.4 has been throwing a "system too lean bank 2" code for about a month now... I've cleaned the MAF, checked for vacuum leaks, found a bad PCV valve, replaced that... this is after doin the "Gotts mod" and straight piping the exhaust. it only throws the code every so often and after cleaning the MAF it took a couple weeks to trip... also replaced the fuel filter and took a while to trip after that too... now a month later im throwing a P0153 "heated oxygen sensor circuit slow response (HO2S-21)" anyone run into this? or have any other ideas on what to check before I start replacing the sensors?

 

jdasilva644,

Did you ever get a fix for this? Mine just started throwing this code along with 0133 and 0402 right before my nice long drive.