Lambda / O2 Off
Rear O2 Sensor Deactivation
What Is It
The rear O2 sensors monitor catalytic converter efficiency. After cat removal or with certain exhaust modifications, these sensors trigger errors and limp mode. We deactivate the rear lambda monitoring while keeping the front sensor active for proper fueling.
Benefits
When You Need It
After catalytic converter removal, decat downpipe installation, or persistent rear O2 sensor faults. Usually combined with Cat Delete.
The Process
Frequently asked
What is Lambda / O2 Off?
The rear O2 sensors monitor catalytic converter efficiency. After cat removal or with certain exhaust modifications, these sensors trigger errors and limp mode. We deactivate the rear lambda monitoring while keeping the front sensor active for proper fueling.
How much does Lambda / O2 Off cost?
From €200. Combined solutions are cheaper bundled — send your make/model/year for an exact quote.
Is it legal / will it pass inspection?
For public-road use in the EU, emissions systems must stay functional to pass KTEO/MOT. Lambda / O2 Off is intended for off-road, motorsport, export or diagnostic use — we’ll always show you the road-legal option first.
Will it damage my engine?
Done properly — custom on your own ECU, calibrated, with your original file saved — no. A cheap generic file can. We never flash a random database file.
Which cars do you cover?
Most modern diesels (VW, Audi, BMW, Mercedes, Ford, Opel and more) and many petrol cars. Send us your make, model and year and we’ll confirm.
Do you use generic files from the internet?
Never. Every solution is developed on your own ECU file with master tools, and your original is always saved so it can be put back.
Emissions solutions are intended for off-road, motorsport, export or diagnostic use. For road use, emissions systems must remain functional.