I started having … come up in my AFR page, and wonky starts, changing fuel trims. No codes, diagnostics of watching O2 sensors said they were fine. Yes, they thought they were fine. But they were reading something as being OK that the engine was telling me different. I replaced all four and never had a problem since, $250 well spent, easily changed two hours tops.
Running O2 sensor that is thinking it’s on Target when it’s actually running the engine pig Rich and you’ll wipe your cylinder walls out in short order. And if it’s smoking white and dumping that much fuel, that’s what’s happening at the moment.