An oxygen-sensor message is more useful when it includes the bank, sensor position and complete code. “Lambda sensor fault” can conceal the distinction between a signal problem and a heater-circuit concern. Preserve the scan before another part is fitted.
Two codes, different questions
P0130 concerns the oxygen-sensor circuit at bank one, sensor one. P0135 concerns that sensor’s heater circuit. The circuit description alone does not prove an internal sensor failure.
Code descriptions HELLA generic diagnostic-code reference. Confirm the full code, suffix and test procedure against the exact vehicle.
Look at the system and repair history
DENSO recommends a systematic diagnosis that considers previous work, correct parts, exhaust leakage, wiring and the relevant signal and heater tests. It also highlights the effect of other engine-management components. A single code should therefore be considered in context. Source DENSO lambda-sensor fault finding.
DENSO distinguishes air/fuel-ratio sensors from traditional oxygen sensors. Their signals are not interpreted in the same way. Avoid comparing a reading with a chart for an unidentified sensor type. Source DENSO A/F and oxygen-sensor bulletin.
Information that helps the next workshop
Include the engine code, sensor location as identified by the vehicle data, and original and replacement part numbers. Describe the warning, running symptoms and any fuel-consumption change. List exhaust, injector, intake and wiring work that preceded the concern.
If the garage has recorded a signal or heater test, include the units, conditions and result. Ask whether the report distinguishes a mixture-related observation from a circuit test. Do not handle a hot exhaust or probe sensor wiring simply to complete an enquiry form.
Choose a supported repair route
Use electrical fault finding for an uncertain circuit concern. An ECU enquiry should include the evidence that points to the controller rather than only the stored sensor code. Keep the original unit and diagnostic history.
AXION Automotive handles specialist electronics enquiries from Didcot and UK garages. Use our assessment checklist, then send the vehicle details and scan report. Vehicle and component support must be confirmed before booking or posting a unit.