OBD Guide

P1E09

Closed Loop Fueling Not Achieved Bank 1 Downstream

P1E09 is an OBD-II diagnostic trouble code meaning: Closed Loop Fueling Not Achieved Bank 1 Downstream. Common causes: rear oxygen sensor malfunction (bank 1), air leaks in the exhaust manifold or pipes. Estimated repair cost: $28–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$28–89 (est.)

Symptoms

  • Increased fuel consumption
  • Unstable engine operation at idle
  • Check Engine light comes on
  • Loss of engine power
  • Increased level of harmful emissions

Causes

  • Rear oxygen sensor malfunction (bank 1)
  • Air leaks in the exhaust manifold or pipes
  • Problems with the catalytic converter
  • Malfunctions in the fuel system (injectors, fuel pump)
  • Problems with sensor wiring or connectors

How to Fix

  1. Check the condition and readings of the rear oxygen sensor bank 1
  2. Inspect the exhaust system for air leaks
  3. Check the condition of the catalytic converter
  4. Diagnose the fuel system (pressure, condition of injectors)
  5. Check the integrity of the wiring and sensor connectors

Related codes

FAQ

What does the P1E09 code mean?

P1E09 is an OBD-II diagnostic trouble code that indicates: Closed Loop Fueling Not Achieved Bank 1 Downstream

What causes a P1E09 error code?

The most common causes of P1E09 include: Rear oxygen sensor malfunction (bank 1); Air leaks in the exhaust manifold or pipes; Problems with the catalytic converter; Malfunctions in the fuel system (injectors, fuel pump).

How do I fix a P1E09 diagnostic trouble code?

To fix P1E09: Check the condition and readings of the rear oxygen sensor bank 1. Inspect the exhaust system for air leaks. Check the condition of the catalytic converter. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1E09?

Yes, but get it checked soon

How much does it cost to fix P1E09?

The estimated repair cost for P1E09 is $28–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat