Hi all, I’m having a persistent Open Loop - Fault (OL-Fault) issue on my Jaguar after replacing the fuel injectors, and I’d appreciate any advice from those who have dealt with something similar. Car Details: Model: [F TYPE - 2015 3.0 Supercharged RWD ] After installing a new injector in cylinder 4 (post specialist removal of a snap off due to corrosion) I checked live data and noticed the following problems: 1. Fuel System Stuck in Open Loop - Fault (OL-Fault) The ECU won’t enter closed loop, meaning it’s ignoring O2 sensor feedback. 2. O2 Sensors Stuck at 1.275V All oxygen sensors (both banks) are reading 1.275V constantly and not fluctuating. This suggests either a wiring issue, ECU fault, or fueling problem. 3. Long-Term Fuel Trims: Bank 1 & 2 = 0.0% (No adjustment) Bank 3 & 4 = -100.0% (Fully cutting fuel trims, very unusual) 4. Wideband O2 Sensor Readings: Bank 1: -0.035mA to -0.051mA (Low activity) Bank 2: 0.887mA - 0.902mA (Some activity) . Possible Causes I Suspect: 1. O2 sensor issue or wiring fault – Could a bad ground or harness problem cause all sensors to lock at 1.275V? 2. ECU not trusting O2 sensors due to another issue (MAF, fuel pressure, etc.) 3. Overfueling or fuel pressure issue – Could the new injectors be over-delivering fuel? 4. Bad MAF sensor – Would a faulty MAF prevent closed-loop operation? Questions: Has anyone seen O2 sensors stuck at 1.275V before? Could a bad MAF or vacuum leak cause the ECU to ignore O2 sensors? What should I check next to force the ECU into closed loop? Any suggestions or ideas would be really helpful! Thanks in advance.

Declan

 

Running OL you maybe can't expect O2 values to be true.

Also, you likely have WIDEBAND sensors and they are NOT voltage-sensed. They are current-sensed so your tool is not helping (or you need to look elsewhere in it).

I know nothing about your engine - not even how many banks it has but 4 sounds unlikely for a 3.0.

Maybe see whether others better use whatever tool you're using or suggest a better tool.