Increased consumption; Troubleshooting

Hello!
A few weeks ago, I had some problems with performance and engine running (jerking on the highway and moderate black smoke even without acceleration; also, strange blowing noises coming from the dashboard area when accelerating).
As the cause, I was able to identify a crack, approximately 5 cm long, in the air intake hose between the LLK (likely a component) and the ZK (likely another component), and I sealed it with tape.
Since then, he's running perfectly again (super performance, no smoking), but I think he's also consuming significantly more fuel (at least 1-2 liters/100 km more than before).
Now, my question to the experts:
1. can the increased fuel consumption somehow be related to the occasional driving with the open crack?
2. How can I systematically investigate the cause of the increased consumption? (I have a fully functional VAG COM, but regarding... I don't really have experience with the measurement blocks in the MStG; maybe someone could tell me which measurement blocks I should pay attention to)?
The troubleshooting via VAG Com was, however, unsuccessful (no errors detected).
Thank you in advance!