Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Currently, i have a Grand Marquis 2001 (GCC specs) with cats removed recently (i have no idea why were those removed) & with P0106, P0109, P0135, P01441, P0155, P0161, P0403, P0443, P0645... With 186411.358 miles... I seek advise & guidance from the professionals with all respect to them. Just to confirm you.. The HO2S11 & HO2S21 are disconnected. (Even if reconnected i still get that codes) Do you want me to check the Power or Grounds ?
Last edit: 5 years 11 months ago by Zaheer. Reason: Added more Info....
