Hi Aston Martin fans. This is my first time being on here but I have a question.. My 2012 Aston Martin Virage started sputtering really bad and after we connected the computer, it showing that cylinder #7 emissions are faulty and you can hear the lifter tapping really bad, I go to that side of the exhaust system and you can hear a difference between the 2 pipes and it smells different also.. Any suggestions..?