Good afternoon Nickolas,
First off, welcome back to just answer. You have the AWP engine installed in your Jetta. The coils installed in the 1.8T have a very high failure rate and have had multiple supercessions of the part number in an attempt to fix this concern. I recommend replacing all four of the coils to prevent misfires from occurring in the future. The coils run about 32 dollars at the dealer, try to purchase the coils from the dealer so that you get the most current part number (do not know it off the top of my head, can get it on Monday). I use NGK plugs in my VW. If you chose to use another brand please use a reputable one like NGK or Bosch. Do not use plugs from Autolite or other lower priced brands. These plugs seem to cause misfires in the 1.8 engine. You do not need the special tool to get the coils out of the cylinder head. I use my fingers to pry up on the coils at the outer edges and have not had any problems getting the coils out of the engine by this method. There is a vacuum reservoir located on the valve cover which covers the number four coil. The reservoir assembly is held in place with a 10mm head nut and three 5mm allen head bolts.
If you have any further questions or need any clarification on the information given, please ask. Max
The check engine light will reset after a number of drive cycles, though I do not remember the exact count (should be always reset the light with a scan tool at work). I believe that you asked about the brake pad warning light during a previous post, but I did not give an answer due to the clutch concern. The brake pad warning light in the instrument cluster should reset as soon as the news pads are installed. You should not need a scan tool to reset this light. The circuit is a simple open/closed loop that activates the waring when the brake rotor wears through the pad sensor. There is sometimes a problem with the wiring between the sensor and the instrument cluster, or, in very rare cases, a problem with the brake pad sensor. An easy way to find out where the problem lies is to use an old pad sensor, cut the wiring and twist the wiring together. This creates a test piece that can easily be connected to the wiring on the knuckle assembly. If the light goes out then the problem is in the new pad sensor, if not, then there is a problem with either the connector or the wiring.
If the "ABS" warning is lit then a scan tool is needed to reset the light. If you want to run a 3" turbo back exhaust system, I would recommend taking a look at what is available for upgrades to your ECM. You will be changing the back pressure in the exhaust system thus you may want to increase the amount of pressure that the turbo is able to provide. Anytime on item is changed there will be an effect on how the fuel injection system operates. Take the time to research some of the VW performance experts that are located online who offer upgrades for your engine system. Take a look at some of the complete packages so you can see what is offered along with a 3" turbo back upgrade. I can think of one GLI that has a 3" exhaust with a performance upgrade to the ECM that has a noticeable increase in HP. Max