01 Taurus, 180k, Vulcan motor
- Original plugs? Misfire. Huge gap. Installed new plugs.
- 1 month later , new timing cover gasket, immediate #3 misfire
- New coil, misfire is gone
- Next day, got 0171 and 0175 code. Bank running rich
Is new coil weak? Suspect? Did misfire affect cat performance?
Only driven 10 miles with new coil