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Information only. This page provides general educational information about fault code P1134. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.

Recommended next steps

Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.

What does P1134 mean?

P1134 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: HO2S-11 (Bank 1 Sensor 1) Transition Time Ratio Error.

Manufacturer-specific notes

Some manufacturers publish additional definitions or variations for this code. Always cross-check with your vehicle's own service documentation.

Acura HO2S-11 (Bank 1 Sensor 1) Transition Time Ratio Error
BMW HO2S Heater Circuit Current Malfunction
Cadillac HO2S-11 (Bank 1 Sensor 1) Transition Time Ratio
Chevrolet HO2S-11 (Bank 1 Sensor 1) Transition Time Ratio
Ford HO2S-11 (Bank 1 Sensor 1) Indicates A/F Ratio Too Lean
GMC HO2S-11 (Bank 1 Sensor 1) Transition Time Ratio
Honda HO2S-11 (Bank 1 Sensor 1) Transition Time Ratio Error
Hyundai HO2S-11 (Bank 1 Sensor 1) Transition Time Switch
Kia HO2S-11 (Bank 1 Sensor 1) Indicates A/F Ratio Too Lean
MINI HO2S-11 (Bank 1 Sensor 1) Indicates A/F Ratio Too Lean
Mazda HO2S-11 (Bank 1 Sensor 1) Indicates A/F Ratio Too Lean
Saab A/F Sensor Micro-Computer Problem
Subaru Front Oxygen Sensor Micro Computer Problem
Vauxhall HO2S-11 (Bank 1 Sensor 1) Indicates A/F Ratio Too Lean

About Emissions codes

Emissions codes relate to systems that control or monitor exhaust gas composition, catalytic converters, oxygen sensors, exhaust gas recirculation (EGR), and the evaporative emissions (EVAP) system. These rarely affect drivability dramatically but can cause MOT failures.

P1134 is one of 258 codes in this category. Browse all Emissions codes →

What we know about P1134 specifically

We record the SAE J2012 standardised definition and the system this code belongs to, but we have not yet published detailed driver-reported symptoms, common causes, or step-by-step diagnostic guidance for P1134.

Rather than invent that information by generating generic content from a template, we leave it out. For specific guidance, the most reliable sources are:

  • your vehicle's own service manual or manufacturer-specific technical bulletins
  • a qualified mechanic with a manufacturer-level diagnostic tool
  • a marque specialist familiar with your make and model

Spotted an issue or have something to add? Mechanics, technicians, and drivers who have first-hand experience with P1134 can submit a correction or expansion. We review every submission before publishing, mechanic submissions are prioritised.

Information only, not professional advice

The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →

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