Ageing or contaminated downstream oxygen sensor (Bank 2 Sensor 2) with a sluggish response; Exhaust leak near the sensor or upstream of it letting in false air; Damaged, chafed or corroded sensor wiring or connector, or high resistance in the signal or earth circuit; Sensor contaminated by silicone, coolant, oil or fuel additives; Fuel trim problem on Bank 2, such as a vacuum leak, weak injector or fuel pressure fault, affecting the mixture swing; Degraded catalytic converter changing the signal pattern downstream; Faulty engine control unit.

P013D

O2 Sensor Slow Response - Lean to Rich Bank 2 Sensor 2.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
1: AreaFuel and air metering
3D: FaultThe specific fault in that area

What it means

P013D is a generic code meaning the downstream oxygen sensor (Bank 2, Sensor 2) is responding too slowly when the exhaust changes from lean to rich. The engine control unit monitors how quickly this sensor's signal switches after a deliberate or natural change in mixture, and it set the code because the transition took longer than expected. Bank 2 is the side of the engine that does not contain cylinder 1, and sensor 2 sits after the catalytic converter.

Symptoms

Engine management light on
Usually no noticeable change in driving
Possible slight rise in fuel consumption
Failed emissions test
Occasionally a rough idle or hesitation if a fuel or exhaust fault is also present

Possible causes

Ageing or contaminated downstream oxygen sensor (Bank 2 Sensor 2) with a sluggish responselikely
Exhaust leak near the sensor or upstream of it letting in false airpossible
Damaged, chafed or corroded sensor wiring or connector, or high resistance in the signal or earth circuitpossible
Sensor contaminated by silicone, coolant, oil or fuel additivespossible
Fuel trim problem on Bank 2, such as a vacuum leak, weak injector or fuel pressure fault, affecting the mixture swingpossible
Degraded catalytic converter changing the signal pattern downstreamrare
Faulty engine control unitrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine temperature, load and fuel trims when the fault set
Check for related codes such as misfires, fuel trim, other oxygen sensor or catalyst efficiency codes and deal with those first
Inspect the Bank 2 Sensor 2 wiring, connector and heat shield for damage, corrosion, water ingress or contamination
Check the exhaust for leaks between the engine and the downstream sensor, including flanges and joints
Check short and long term fuel trims on Bank 2 at idle and at steady 2,500 rpm for signs of a lean or rich fault
Watch the live downstream sensor signal on a scan tool while snapping the throttle open and closed, checking that it switches quickly and cleanly
Check the sensor heater circuit and the sensor's supply and signal wiring for resistance and voltage, using the manufacturer's specification for the model
Look for signs of coolant, oil or silicone contamination on the sensor tip if it is removed

How to fix

Replace the Bank 2 Sensor 2 oxygen sensor if the live data shows a slow or lazy response
Repair or replace damaged wiring, terminals or connectors in the sensor circuit
Repair any exhaust leaks and replace faulty gaskets or sections
Correct the underlying fuel or air fault, such as a vacuum leak, injector or fuel pressure fault, then re-check the trims
Fix the source of any contamination, such as a coolant or oil leak, before fitting a new sensor
Replace the catalytic converter only if testing confirms it has failed

Can I keep driving?

Low severity

The car can normally be driven while you arrange a repair, as this fault rarely affects driveability. Do not leave it for long, because a related fuel or exhaust fault could harm the catalytic converter and the car may fail its emissions test.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.