P1137 Fuel trim too rich, additive (bank 1)

By: Diagno editorial team · Updated: 2026-10-15

P1137 means: Fuel trim too rich, additive (bank 1). There is too much fuel in the mixture and the computer can no longer reduce it on its own. Drive gently and have the car checked soon. The repair usually costs about €50–600 in Estonia. The most common cause: leaking injector.

What it means

There is too much fuel in the mixture and the computer can no longer reduce it on its own.

This is a make-specific code (VAG). The exact meaning can vary by model and year.

What you may notice

• Engine light on
• Higher fuel consumption
• Black smoke or fuel smell from the exhaust
• Sooty spark plugs

What could be wrong

1. 1Leaking injector
2. 2Fuel pressure too high
3. 3Mass air flow sensor reading wrong
4. 4Clogged air filter
5. 5Faulty oxygen sensor

Repair difficulty: Moderate

What you can check yourself

Check that the air filter is clean. Notice whether the exhaust smells of fuel. You can check the simple things yourself, but the repair is best done in a workshop.

How we fix it

1. We check fuel trims and sensor readings on the diagnostic tool
2. We measure fuel pressure
3. We check the injectors for leaks
4. We replace the faulty part

Standard SAE description: Long Term Fuel Trim add. Fuel, Bank 1 System too Rich