Integra Hybrid rough running

Given the symptoms you describe – poor starting, increased fuel consumption, reduced power, uneven idling, and stalling – a defective injection nozzle certainly seems plausible. A dirty or malfunctioning injector will disrupt the proper fuel atomization and combustion process. Have you noticed any unusual smells from the exhaust, or any changes in the engine's sound? Also, has the car's computer thrown any error codes?

No unusual smells and no error codes. Someone else mentioned it could be the injection valve itself, and not just dirty ones. Is there a way to confirm this? I'm worried about the replacement cost!

Indeed, a faulty injection valve is a strong suspect, especially given the absence of error codes (sometimes these issues don't trigger them immediately). Confirming this definitively often requires specialized diagnostic equipment to measure the fuel injector's spray pattern and volume. Considering the potential impact on performance and emissions, and the replacement cost involved, I'd strongly advise taking it to a reputable workshop for a proper diagnosis and repair. It's best to avoid DIY fixes on modern hybrid engines, as improper handling could lead to further complications.

Thank you for the detailed response! I had the injection nozzles checked and you were right. Turns out one was defective. The workshop confirmed it and completed the replacement. Total repair cost was 515€. Runs like new again!