If it threw the AMM code put the new one back on that means at one point the AMM did fail, also same for the Lambda sensor, it will cause the rich/lean code to to throw as well as when the sensor is out it runs rich or lean, id replace the Lambda sensor as see if everything goes back to normall thats a sensor that will cause everything to run all wacko, heck out here in california without one of those you cant even pass your smog check.