# Q: Do i need wideband oxygen sensor? ## The short answer is yes The longer answer is also yes. You need a wideband because a narrowband only tells you if you are RICH or LEAN, not HOW RICH or HOW LEAN. How are you going to target 13:1 AFR at wide open throttle with a narrowband? Hint: it isn't possible. PS: if you are looking to debate or double-check anything here - please don't. You _absolutely need_ a wideband oxygen sensor. ## Q: So I need it for initial calibration, what about once calibration is done? A: With weather changes and life happening it's better to keep the wideband and enjoy rusEFI closed loop fuel correction functionality. ## Q: Shall I get Innovate wideband controller? A: rusEFI advices AGAINST Innovate wideband controllers. [WBO](WBO)