Other car is 2016 HR-V bought new, now has 150K mi. Have been on this forum for some years, per '09 Fit (still running great in part due to you folks). Turns out HR-V forum is pretty lame. Maybe because they don't get the sporty mods that the Fit does, and the mechanical knowledge base is less. I dunno. What I do know is that the HR-V and Fit share a lot of the same attributes, and some similar parts and design. In this case the int and exh are reversed but the principles should apply- replaced injectors, now the fuel pressure drops like there is an air leak (no gas leak but smell gas on occasion as I think small amount of raw fuel may be dripping into cylinder, when sitting while engine not running). Sprayed thoroughly outside fuel rail, injectors, w/MAF cleaner to test leakage and no change in RPM. When on fwy drives going downhill throws code PO172 but engine does not stumble. As a matter of fact, aside form stumbling a bit to get started, car is running smoothly w/good power. Oddity is that indicated mpg is crazy high- 51 on fwy and 44 around town but net at the pump is approx 32.
Will do ohm test and "listen" to injectors w/ear scope to check on each unit.
Don't think it is fuel pump/filter or regulator as the car drives well. Need to add that I dinged (forced into holes) initial set of injectors which threw a lot of codes and I may have splashed a lot of fuel onto the O2 sensor (will replace soon as the part comes in) but outside the stumbly startup, old car runs well.
Am hoping there are other combo HR-V/Fit owners that might have thots as to loss of fuel/startup pressure (did not even disconnect fuel rail- just swung out to replace injectors and swung back in).
Sorry for the cross-over inquiry.
Huff

 

is there a fuel pump recall on the HRV ? i had one on my '19 Fit , but it didn't behave like this . the code should tell you something . also , you could have your oil analyzed by Blackstone .
they can tell you if you've got too much fuel dumping into your crankcase

 

Update- (re) replaced the injectors and vacuum-leak-down checked fuel rail and it seem to hold pressure. Key to installing injectors is cleanliness, apparently. Swabbed/vacuumed out the holes/seats in the head, loosened the local plastic loom cover for the connectors to make room to seat the whole assembled-with injectors/connectors fuel rail, which helped quite a bit as the metal contacts are delicate and get mangled easily if attempt to connect after rail seated (had to straighten one female metal conn). Also used new "green" fuel line connector (white plastic barrel cover broke so taped over w/silicone tape- I love this tape).
Cleaned EGR, PCV, throttle body, replaced O2 sensor and the car runs like near new at 150K mi. Hesitation is gone, starts right up. Short and Long Term fuel trim seems to be okay. Crazy-high mpg is coming back towards normalcy.