What's up guys, My has stang been acting up for last month or two! Its funny when your weekend ride becomes your daily for a little while and you start getting little issues with it, oh the joy!!! Moving on...these DTC's I am not familiar with because I haven't really encountered a problem like this before. When the car is in closed loop, on certain mornings it will have a rough idle to shake the car then go away. Sometimes it doesn't happen at all and sometimes it does. I really feel it when the car is accelerating in its OD gear at about 1500 rpms. You do not feel it when your on the gas but if I were to get on the gas in any gear between 1500-2000 rpm, you feel the car lose a bit of power sometimes. Here are DTC's below: P0131 - Oxygen Sensor Circuit Low, Voltage Bank 1 Sensor 1 P0155 - Oxygen Sensor Heater Circuit, Bank 2 Sensor 1 P1131 - Lack of HO2S11 Switch - Sensor Indicates Lean P1151 - Lack of HO2S11 Switch - Sensor Indicates Lean Do you think my O2 sensors are going out? My gut feeling is that there is another issue at hand. I believe there could be minor vacuum leaks around the engine and I need to dig in. I have Bosch sensors if anyone wants to know the brand and they been on the car for almost 30-40k.