I have had to replace 2 COPs on my 2002 F-150 with the 4.6L engine; 4X4; 105,000miles. When those went bad, an engine code was set in the OBD. I am experiencing another failing COP, (I think), but no code has been set. Is there a diagnostic method for determining which one is failing other than buying a new one; installing it; taking a test drive and then move it again if it isn't the correct one? I don't have the green to replace all at once!
Thanks!