[Overlander23]

Occasionally, I've been getting a P0172 code thrown (bank one too rich). I'm wondering if a vacuum leak could cause this? I searched and found references to vacuum leaks and P0171 (too lean), but could this also throw a P0172?

Monitoring short term fuel trims at startup, I'm getting ~-22% which seems way rich. Blipping the throttle zeros out the STFT, and once the engine is warm the trim stabilizes at around -9% to -5%... but it's not sitting at the typical +- 3%, and it never sits in the positive range.

Is it common to be so rich on cold startup?

Thanks!