P013EO2 Sensor Delayed Response - Rich to Lean Bank 1 Sensor 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The downstream oxygen sensor (sensor 2, after the catalytic converter) is used for fine mixture trim and to monitor the converter. 'Delayed response' means the sensor starts reacting too late, or does not reach the target level at all, after the mixture has changed. This code covers the rich-to-lean direction, usually tested during deceleration fuel cut-off. GM checks whether the signal falls below 450 mV before about 45 g of air have passed after the forced change; failing needs two trips. Ford counts it as stuck in range if the sensor does not drop below 0.1 V within 5–10 s of fuel cut-off. Bulletins often point elsewhere: Audi fixed P013E with software and said not to replace the sensor, VW names exhaust leaks or the converter. CARB requires separate detection of slow and delayed faults in each direction (phased in from 2009 for downstream and 2011 for upstream sensors).
- What you may notice
- Check engine light on
- Usually no noticeable change in driving
- Catalyst monitor may stay incomplete (inspection readiness missing)
- With a converter cause, P0420/P0430 may follow
- Likely causes
- LikelyDownstream oxygen sensor aged or contaminated (soot, oil, silicone, coolant)
- PossibleExhaust leak between manifold/turbo and the sensor
- PossibleConverter faulty or non-original with different oxygen storage
- RareControl module software too sensitive (update available)
- RareSensor connector or wiring with contact resistance
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €60 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.