Intermittant chugle(idle),poor throttle response

Your hetred o2 sensor is also what some manufacturers call a fuel/ air metering sensor, primarily because this is exactly what it does. with a faulty 02 sensor the computer doesn't know if the engine is running rich or lean, there for causing a rough idle, repair this as quickly as possible because damage can be done to the catalytic convertors. this can cost upwards of 1000 bucks to replace depending which engine. no matter which engine you have, replace both o2 sensors in the bank that is causing the problems, this is more important with the gm line than most but holds true to all vehicles