[Wanted_M]

Three things I'd check;

1. Once you come home and shut off car, turn ignition on, open log and monitor your HPFP or rail pressure. If you have a leaky injector, the pressure over time in the rail will drop by several hundred for sure. Write down pressure on shutdown then come back an hour or two later or next morning and turn ignition on, start log to view rail pressure without starting car.

2. Inspect plugs tips and see which one is wet or smells like raw fuel, if wet or smelly, then you know that cylinder probably has a bad injector.

3. Drain a quart or so of oil and see if oil smells like fuel.

If you injector is failing open, it will drip drip drip causing the puff of smoke on start up and lower rail pressure. Is your car taking longer to crank/start? That's also an indication of lower rail pressure/spark blow out on start up due to raw fuel.

Hope this helps you out bro and keep us posted. You're doing a good job troubleshooting.

Based on what I mentioned above, that's how I found one on my Audi.