B7 CKRA P0299

2014 Passat TDI SEL DSG 95,000m. (CKRA with rawtek kit installed)

The other day I was driving home from work and my engine randomly stalled on me while waiting in traffic. Whenever I tried to restart it - it would crank, start, and stall.
After getting it towed home I scanned it and got a pending p0236 (Boost Pressure sensor). The next morning it started up and maintained idle speed but had lots of black smoke out of the exhaust. Also no throttle response (limp mode?). Per the check engine light I replaced the boost pressure sensor with an OEM replacement. I inspected the intercooler and charge pipe only to see light/minimal oil deposits and cleaned it the best I could.

I then took the battery out and had it fully recharged at a local parts store. The battery tested good. The alternator holds 14V at idle speed. Now sometimes it starts and idles (blowing smoke) and sometimes it just stalls after starting. I scanned it again to find P0299 (turbo underboost condition). The turbo actuator was remotely tested with a hand held vacuum pump confirming it holds vacuum. All surrounding vacuum hoses were inspected and no vacuum leak was found.

Currently the car starts, idles with excessive smoke from tail pipe, and sometimes stalls. P0299 code present. No throttle response. Lets say my turbo failed - wouldn't I still have some throttle response? Anyone else encounter this? I never had any issues with the engine prior to this.



History: I purchased the car last year with 83,000.

88,000:
Rawtek catback (deleted DPF, EGR)
Running stage 0.5 Eco-tune (no DSG tune)

85,000:
OEM Timing belt water pump replaced. DSG fluid serviced.

All service was recommended and performed by a TDI specialist VW technician.