F Type Running Rich: Fuel & O2 Sensor Warning Signs

Had similar symptoms with my Jaguar XK (2011), heavy fuel consumption combined with jerky acceleration pointed straight to problematic fuel injectors. The carbon buildup was causing uneven fuel spray patterns, making the engine run rich. Initial diagnostic revealed two fuel injectors were not atomizing fuel properly. Running rich means wasting fuel and potentially damaging the catalytic converter if left unchecked. The check engine light was triggered by the oxygen sensor detecting the rich mixture. This is a serious issue requiring prompt attention. Left unrepaired, faulty fuel injectors can lead to: Further decline in fuel economy, Rough idling, Potential catalytic converter damage, Engine misfires, Failed emissions tests The repair involved removing and cleaning all injectors, replacing two that were beyond salvage, and doing a full system diagnostics. Also changed the air filter since it was due. The difference in performance was immediately noticeable, smooth acceleration returned and fuel consumption normalized. Recommend getting proper diagnostics done to pinpoint exactly which injectors are problematic. This is not a job for inexperienced mechanics as it requires specialized equipment and expertise with fuel injection systems.

Thanks for sharing your experience. Your symptoms do sound identical to what I faced. After getting mine fixed, the F Type went back to running like a dream. The sluggish acceleration disappeared completely after the intake manifold cleaning and fuel injector replacement. Quick question, do you remember roughly what you paid for the full repair? Also curious if you have had any recurring issues since getting it fixed? My fix was a few months back but would love to know what to watch out for in the future.

After getting the injector replaced and the entire system properly diagnosed, the total came to 515€. The repair eliminated the rich fuel mixture completely, no more check engine lights or poor fuel economy issues. The oxygen sensor readings went back to normal, confirming the engine was running at optimal levels. Since the repair 8 months ago, everything has worked flawlessly. The acceleration is crisp, and fuel consumption returned to factory specs. No recurring problems at all. Just keep up with regular maintenance and watch for any sudden changes in fuel economy or engine performance. Early detection of any issues helps prevent damage to the catalytic converter or other expensive components. Make sure to use high-quality fuel and follow the recommended service intervals. A properly maintained fuel injection system should give you years of trouble-free operation.

Thanks for the input. I finally got the courage to visit a different specialist who actually knew what they were doing. The whole ordeal cost me 480€ but it was worth every cent. The air-fuel ratio is now perfect and the car runs like new. The mechanic thoroughly cleaned the intake manifold and replaced two faulty injectors. The check engine light disappeared right after the repair. They also discovered my air filter was pretty clogged, so that got changed too. Been driving for about 3 months now and the difference is night and day. The acceleration is smooth, no more jerking, and my fuel consumption dropped back to normal levels. Really glad I didn't wait any longer, the mechanic mentioned I could have ended up with catalytic converter damage if I had kept driving it in that condition.