Hey all, been digging into some quirks with my 2021 Yukon XL (5.3L, 2.5 months old, still under warranty). Noticed it’s down a quart of oil since I got it, but after warming up, the dipstick reads full weird, right? Using a BlueDriver, I’ve been logging fuel trims:
- Highway (66 mph, Tiptronic 9th, AFM off): Long-term trims steady at -9% to -10% on both banks.
- City driving: Seems richer, haven’t logged exact numbers yet, but I’ll check. Somewhere in the -12-15
- Bonus: Smelled fuel at startup today, faded after running.
Coolant temp’s steady at 200°F, so that’s fine. Thinking MAF, O2 sensors, or maybe a leaky injector since it’s rich across both banks. Oil’s synthetic (prob 0W-20), planning a change Tuesday. Any thoughts on what to tell the dealer? AFM/DFM a factor?
- Highway (66 mph, Tiptronic 9th, AFM off): Long-term trims steady at -9% to -10% on both banks.
- City driving: Seems richer, haven’t logged exact numbers yet, but I’ll check. Somewhere in the -12-15
- Bonus: Smelled fuel at startup today, faded after running.
Coolant temp’s steady at 200°F, so that’s fine. Thinking MAF, O2 sensors, or maybe a leaky injector since it’s rich across both banks. Oil’s synthetic (prob 0W-20), planning a change Tuesday. Any thoughts on what to tell the dealer? AFM/DFM a factor?