My 2005 CTT is running fine, except for slight hesitation under WOT at highway speeds. Here are the codes from my iPhone OBDII reader:

current
p0441

pending
p2189
p0300
p0306
p0305
p2187

the coils were replaced by PO around 12k ago. not sure about plugs.The check engine light came on shortly after an oil change. Can the oil cap be responsible for a few of the codes?

Any recommendations?

thank you

 

Three of those pending codes are misfires(P0300/P0305/P0306) most likely plugs an/or coils. Your P0441 is likely evap purge valve(thin driver side vacuum hose, running behind plenum), and/or gas cap.

 

Ordered a new gas cap and the valve. Will try that fix first. Would that valve and gas cap cause the hesitation at wot? Perhaps low fuel pressure?