The Quick Answer above is the generic definition. What follows is the model-specific detail for the Volkswagen models that log P0173.
DTC/P0173·Volkswagen
P0173 on Volkswagen: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeveritySafe to drive (short-term)Volkswagen
P0173 on a Volkswagen means the ECU has pushed long-term fuel trim on Bank 2 to the limit of its correction range and still cannot maintain the target air-fuel ratio. Because P0173 only affects one bank, it usually points to something specific to Bank 2 (a leak, a degraded sensor, or a dirty injector on that bank) rather than a whole-engine issue like a clogged fuel filter that would affect both banks. VW, Audi, Skoda and SEAT apps often show this code as P017300; the last two digits are a failure-type byte.
Typical repair cost, all makes€70 - €420
Connect any standard Bluetooth OBD2 adapter to your Volkswagen and Skanyx tells you what P0173 means on that engine, whether it is safe to keep driving, and what the fix should cost. Free on iPhone and Android.
Get Skanyx freeWhat does P0173 mean on a Volkswagen?
Volkswagen Touareg
2010-2024On the Touareg 3.0 TFSI petrol V6, P0173 is typically driven by Bank 2 lambda sensor ageing or an air leak on that side. Access on the Touareg is tight, and shop labour costs are higher than on smaller VW group V6 applications.
What causes P0173 on a Volkswagen?
Beyond the generic causes listed on the main P0173 page, these are the patterns noted for Volkswagen models:
Volkswagen TouaregBank 2 lambda sensor aging on 3.0 TFSI
Volkswagen TouaregAir leak at intake seals or hoses on the bank 2 side
How to diagnose P0173 on a Volkswagen with OBD2
Follow these steps to pinpoint the root cause of P0173:
- Read live data: focus on short-term and long-term fuel trim for Bank 2. A long-term trim above +20% or below -20% confirms the bank has been hitting its limits
- Compare Bank 2 trims to Bank 1. If only Bank 2 is out of range, the cause is bank-specific (one injector, one sensor, one manifold gasket section)
- Smoke-test the intake on Bank 2 specifically. On V engines, intake manifold gaskets fail one side at a time as plastic shrinks unevenly
- Swap the upstream sensors between banks and re-check live data. If the high trim follows the sensor, replace it; if it stays on the original bank, focus on mechanical causes
- Inspect for exhaust leaks ahead of the Bank 2 upstream sensor. A small leak can pull fresh air into the exhaust stream and trick the sensor into reading lean
How much does P0173 cost to fix on a Volkswagen? (EUR)
Estimated repair costs for P0173 in EUR, compiled across makes. Expect Volkswagen parts and labour towards the upper end of each range.
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Codes related to P0173
These codes are often seen alongside P0173 or point to related issues, on any make:
Looking for the full P0173 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0173 guideSkanyx · Volkswagen
Diagnose P0173 on your Volkswagen
Your car logged P0173. Skanyx reads it on any standard Bluetooth OBD2 adapter, tells you whether it is safe to keep driving, and shows the €70-€420 repair range so you know the number before a shop quotes you. Free on iPhone and Android, and you do not need to be a mechanic to read it.
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