P1134Manufacturer-specific code

P1134 Code: O2 Sensor Transition Time Ratio (GM, Bank 1 Sensor 1)

On General Motors (Chevrolet, GMC, Buick, Cadillac), the P1134 code points to the O2 sensor transition time ratio (bank 1 sensor 1). Fuel use runs slightly higher. A tired sensor or an exhaust leak is the usual cause.

Severity
Medium
Can I keep driving?
Yes, no immediate risk
Estimated cost
$50 to $200
Difficulty
Easy
System
Air and Fuel
Applies to
Depends on the manufacturer

Common in: Chevrolet

Updated Reviewed by Renzo Chacca

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What the P1134 code means

P1134 is a manufacturer-specific code: the 1 in the second position means each automaker defines what it stands for, not the generic standard. The most widespread definition is the one used by General Motors (Chevrolet, GMC, Buick, Cadillac). If your vehicle is another brand, confirm the code text with a scan tool that supports that manufacturer.

ManufacturerMeaning of P1134
General Motors (Chevrolet, GMC, Buick, Cadillac)O2 sensor transition time ratio (bank 1, sensor 1)

GM measures how long the front oxygen sensor takes to go from rich to lean and from lean to rich. A healthy sensor is equally fast in both directions.

The computer sets the P1134 code when one of the two times is much longer than the other: the sensor is aging or there is an exhaust leak.

Before you repair anything, confirm the make, model, year and engine. With manufacturer codes, the same number can change even between engines from the same brand.

P1134 code symptoms

  • Check engine light on.
  • Slightly higher fuel use.

Likely causes of the P1134 code

  1. Aged oxygen sensor. Confirm it by comparing its reading with the actual value.
  2. Exhaust leak ahead of the sensor. Confirm it by comparing its reading with the actual value.
  3. Sensor contamination. Confirm it by comparing its reading with the actual value.

How to diagnose the P1134 code step by step

  1. Graph the sensor signal and compare the rise with the fall.
  2. Look for exhaust leaks.

How to fix the P1134 code

  • Replace the sensor.
  • Repair exhaust leaks, then clear the P1134 code and confirm it does not return.

Technical reference data

  • Transition of a healthy sensor: under 100 ms in each direction.
  • P1xxx codes are manufacturer-specific: confirm the definition with a scan tool that supports your brand.
  • Values are approximate: check the manufacturer data for your vehicle.

Brand-specific notes

Common on Chevrolet, GMC, Buick, Pontiac and Cadillac.

If your vehicle is another brand, check the table above for the meaning its manufacturer gives the code, and confirm it with a scan tool that supports that brand.

Frequently asked questions about P1134

What does the P1134 code mean on a GM vehicle?
It points to the O2 sensor transition time ratio (bank 1 sensor 1). The sensor is slower in one direction than the other, and fuel use runs slightly higher.
Does P1134 mean the same thing on every brand?
No. It is a manufacturer code, and on other brands it may not exist or it may mean something else.
Can I drive with a P1134 code?
Yes. The effects are mild, mostly a bit more fuel use. Plan the repair anyway, because a tired sensor keeps getting worse.
How much does it cost to fix P1134?
On a GM vehicle the cost runs from about $50 to $200. A new oxygen sensor accounts for most of it, and an exhaust leak repair varies.
Will a P1134 code clear itself?
Not for long. An aging sensor or an exhaust leak does not repair itself, so the light comes back after you clear it.
What is the most common cause of P1134?
An aged front oxygen sensor. Exhaust leaks ahead of the sensor and sensor contamination are the other causes.

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Questions about the P1134 code

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