a slight vibration and feeling a little loose on my golf mark 4 1.8 turbo gti

Did you check engine/trans mounts

OK ladies engines this is easy you need to check the value or the voltage of either your upstream or your downstream O2 sensors you’re probably getting an egg smell it’s not cranking as well as it could bad gas mileage idols hard probably loud what’s happening is either one of your O2 sensors close likely the one in bay one sensor one being your upstream the one right before your catalytic converter is going dead and you’re not getting a voltage to it or youR catalytic converter itself is clogged problem is your fuel is running either too rich or too lean this is causing all sorts of problems and can eventually cause you to have to put in a new catalytic converter is it trying to figure out what to do with the excess or the lien amount of gas and that can cause what you think would be a bad battery or your EPC light to come on and your card is shut off you need to do a tuneup on your car Plugs and wires both O2 sensors pre-and post catalytic converter and probably run a catalytic converter cleaner through your system and that’s if your catalytic converter doesn’t need replacing after you do that you have no more problems