P0173: Fuel Trim Bank 2
What Does P0173 Mean?
P0173 is a diagnostic trouble code indicating: Fuel Trim Bank 2. This code relates to the fuel and air metering system. It has been reported in NHTSA complaints across 1 different vehicle models.
Symptoms of P0173
- ⚠️ Check engine light illuminated
Common Causes
- 🔍 Intake manifold or gasket leak
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
"AFTER HAVING THE CHECK ENGINE LIGHT COME ON, WE TOOK THE CAR TO THE DEALERSHIP WE PURCHASED IT FROM TO PERFORM A DIAGNOSTIC AFTER RECEIVING CODES P0170 AND P0173 (MB CODES 2092/2096) WHICH MB CLASSIFIES AS "MIXTURE IN RIGHT / LEFT CYLINDER BANK IS TOO RICH WHEN IDLING" AND WERE TOLD WE WOULD NEED TO"
— Mercedes-Benz C-Class owner, 12/21/2011
Source: NHTSA Complaints Database
Most Reported Vehicles for P0173
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | MERCEDES-BENZ C-CLASS |
Frequently Asked Questions
Can I drive with this code?
Will this code cause my car to fail emissions?
How much does it typically cost to fix?
What To Do Next
Possible Fixes
- 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
- 🔧 Clean or replace the mass air flow (MAF) sensor; check for vacuum leaks
- 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.