P0171 on Opel
System Too Lean (Bank 1)
P0171 on Opel vehicles indicates system too lean (bank 1). Au7o has documented this code across 1 Opel model — most commonly on Insignia. This code means the engine's computer has detected that the air-fuel mixture on Bank 1 (the side of the engine with cylinder #1) is running too lean — meaning there is too much air relative to fuel. The computer watches the oxygen sensors and has had to add a large amount of extra fuel (long-term fuel trim) to try to compensate, but it has hit its correction limit. A lean condition can cause rough idle, hesitation, reduced power, and over time can run the engine hotter than normal. It usually points to either unmetered air leaking into the engine or not enough fuel being delivered. Typical repair costs on Opel range from $120 to $600, depending on the specific model and root cause.
Common Causes of P0171
- •Vacuum or intake air leak (cracked hose, gasket, or PCV system)
- •Dirty or failing mass airflow (MAF) sensor
- •Weak fuel pump or restricted fuel filter
- •Clogged or dirty fuel injectors
- •Faulty or aged upstream oxygen sensor
- •Leaking intake manifold gasket
- •Low fuel pressure or failing fuel pressure regulator
- •Exhaust leak ahead of the oxygen sensor
P0171 on Opel by Model
Opel Insignia(1 issue)
- Insignia A Flex-Pipe Exhaust Failure2008-2017
Insignia A front exhaust flex section cracks/fractures around 80,000-150,000 km, especially on diesels. Produces loud rattling/blowing under acceleration, smell of fumes in cabin, and triggers a fault if the lambda sensor is downstream of the leak.
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View P0171 across all makes →Frequently Asked Questions
What does P0171 mean on Opel?▼
P0171 stands for "System Too Lean (Bank 1)." This code means the engine's computer has detected that the air-fuel mixture on Bank 1 (the side of the engine with cylinder #1) is running too lean — meaning there is too much air relative to fuel. The computer watches the oxygen sensors and has had to add a large amount of extra fuel (long-term fuel trim) to try to compensate, but it has hit its correction limit. A lean condition can cause rough idle, hesitation, reduced power, and over time can run the engine hotter than normal. It usually points to either unmetered air leaking into the engine or not enough fuel being delivered. On Opel specifically, this code is documented across 1 model.
What causes P0171 on Opel vehicles?▼
Common causes on Opel: Vacuum or intake air leak (cracked hose, gasket, or PCV system), Dirty or failing mass airflow (MAF) sensor, Weak fuel pump or restricted fuel filter, Clogged or dirty fuel injectors, Faulty or aged upstream oxygen sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0171 on a Opel?▼
Repair costs on Opel range from $120 to $600, depending on the specific model and root cause.
Which Opel models have P0171 documented?▼
Au7o has documented P0171 on 1 Opel model: Insignia.