P0173 : Fuel Trim Malfunction (Bank 2)

P0173 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.

P0173 est un code defaut lie a systeme de carburant, classe en gravite moderate. Lorsque le calculateur de ton vehicule detecte cette condition, il enregistre P0173 et allume le voyant moteur.

Si ton vehicule a declenche P0173, tu peux remarquer un ou plusieurs de ces symptomes :

• Check engine light on
• Rough or uneven idle, especially in Park or Neutral
• Slight hesitation during acceleration
• Reduced fuel economy on one bank
• Possible faint fuel or sulfur smell from the exhaust

Voici les causes les plus courantes de P0173, classees selon la probabilite qu'elles soient en cause :

En general oui, pour des trajets courts. The engine can typically still be driven, but a fuel trim out of range on one bank degrades fuel economy and risks catalytic converter damage over time. Fix within a couple of weeks.

Suis ces etapes pour identifier la cause profonde de P0173 :

1. 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
2. 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)
3. Smoke-test the intake on Bank 2 specifically. On V engines, intake manifold gaskets fail one side at a time as plastic shrinks unevenly
4. 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
5. 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

Les couts de reparation de P0173 varient selon la cause profonde et ton vehicule. Voici des estimations courantes :

P0173 se comporte differemment selon ton vehicule. Selectionne ta voiture ci-dessous pour des causes propres au modele, les problemes connus et des estimations de couts ajustees :

Ces codes apparaissent souvent avec P0173 ou indiquent des problemes connexes :