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).
Medium severity. Can I keep driving?Yes, you can normally drive in moderation, but get it repaired soon: you will use more fuel and the catalytic converter can be damaged over time.
Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank. Sensor 2 is the sensor after the catalytic converter.
Symptoms
- 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
Most likely causes
- Downstream oxygen sensor aged or contaminated (soot, oil, silicone, coolant)
- Exhaust leak between manifold/turbo and the sensor
- Converter faulty or non-original with different oxygen storage
- Control module software too sensitive (update available)
- Sensor connector or wiring with contact resistance
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: easy
- It affects emissions.
What each character of P013E means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 1: Air and fuel
- 3E: Specific fault in that system
Frequently asked questions
Can I keep driving with code P013E?
Yes, you can normally drive in moderation, but get it repaired soon: you will use more fuel and the catalytic converter can be damaged over time.
What causes code P013E?
The most common causes are: downstream oxygen sensor aged or contaminated (soot, oil, silicone, coolant); exhaust leak between manifold/turbo and the sensor; converter faulty or non-original with different oxygen storage.
Related codes
- P013FO2 Sensor Delayed Response - Lean to Rich Bank 1 Sensor 2
- P013AO2 Sensor Slow Response - Rich to Lean Bank 1 Sensor 2
- P014AO2 Sensor Delayed Response - Rich to Lean Bank 2 Sensor 2
- P0139O2 Sensor Circuit Slow Response Bank 1 Sensor 2
- P2270O2 Sensor Signal Biased/Stuck Lean (Bank 1, Sensor 2)
- P0420Catalyst System Efficiency Below Threshold Bank 1
Sources
- law.cornell.edu: 13 CCR 1968.2
- gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
- newtonnet.co.uk: fordobd2012
- static.nhtsa.gov: MC 10127997 9999
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.