97 explorer XLT pops p0442 randomly

[Jerryinwilliamsport]

My 97 explorer XLT 5.0L pops small eval leak code whenever it feels I need to be annoyed. Had a rusted through fuel tank a couple years ago. Got a junkyard tank, cleaned it up, applied rust converter /inhibitor/encapsulator to all sanded down surfaces. Everything went well. Now have P0442 code. I scan w/KOER no codes. Check mem codes come up w/P1000 (obd not ready and P0442. Replaced fuel cap with new Motorcraft cap. Clear mem codes and am good for a couple weeks until the check Engine lamp comes in. Same two codes in mem codes w/o any current KOER codes. Baffled.

 

[Rick Rock]

What condition are your filler neck and vent hose? A small hole or Crack that can expand when warm or if there's a significant vacuum, such as when it's low on gas. (Assuming your tank don't leak and your hoses are on tight)