Hi all, 99 GTi 1.8T AGU
Yesterday I installed a Diverter Valve because when bought the car it didn’t have one (crazy I know). It has a fmic and cold air induction with silicone intake.
I recently have replaced the valve cover gasket as I was getting oil on the spark plug wells but didn’t start it till I had the DV installed.
Sooooo, took it for a short test run and only got to second gear when the engine lost power and died on me. When I changed from 1st to second it made a backfire type sound but I don’t think it was a backfire (not as loud).
I towed it back into my garage but still can’t get it started (does turn over). I have also recently replaced the following: crank angle sensor, coolant temp sensor, ignition amplifier, spark plugs.

Any help is appreciated