What Does P0172 Mean on Your 2022 Acura TLX?
A P0172 trouble code on your 2022 Acura TLX indicates that the engine control module has detected an overly rich air-fuel mixture on Bank 1. The 2022 TLX comes with two engine options: a 2.0-liter turbocharged 4-cylinder producing 272 hp and a 3.0-liter twin-turbo V6 producing 355 hp in the Type S. On the 2.0T inline-4, Bank 1 is the only bank. On the 3.0T V6, Bank 1 is the cylinder bank containing cylinder 1.
A rich condition means the engine is receiving too much fuel for the amount of air entering the combustion chamber. This affects performance, fuel economy, and emissions.
Symptoms You May Notice
- Check engine light illuminated
- Decreased fuel economy below the rated 22/31 mpg (2.0T) or 19/25 mpg (Type S)
- Rough idle or slight engine vibration
- Black or sooty exhaust smoke
- Fuel smell from the tailpipe
- Sluggish throttle response
- Possible misfires under certain conditions
Common Causes of P0172 on the 2022 Acura TLX
- Dirty MAF Sensor - The mass airflow sensor is a top cause on both the 2.0T and 3.0T engines. Oil mist from the turbo intake path can contaminate the sensing element, causing it to underreport airflow.
- Boost System Leak - Both TLX engines are turbocharged. Any leak in the charge pipes, intercooler hoses, or blow-off valve will reduce actual boost pressure while the ECM fuels for expected boost.
- Leaking Fuel Injector - Both engines use direct fuel injection. A leaking injector on Bank 1 will add unwanted fuel to the combustion chamber.
- Faulty Upstream O2 Sensor - A degraded oxygen sensor that reads lean when the mixture is actually correct will cause the ECM to command additional fuel.
How to Diagnose P0172
- Read all stored codes - Check for additional codes related to MAF, boost, O2 sensors, or misfires.
- Check fuel trim values - Negative long-term fuel trims beyond -10% confirm the rich condition.
- Inspect and test the MAF sensor - Remove, inspect for contamination, clean with MAF cleaner, and compare readings to specifications.
- Perform a boost leak test - Pressurize the intake system to find leaks in charge pipes and connections.
- Test O2 sensor response - Monitor upstream O2 sensor switching speed and voltage range with a scan tool.
- Check fuel injector operation - Perform injector balance and leak-down tests.
Repair Options and Cost Breakdown
- MAF Sensor Cleaning - $15-$30 for spray cleaner. Quick 10-minute DIY job.
- MAF Sensor Replacement - $160-$350 with parts and labor.
- Boost System Leak Repair - $100-$450 depending on the component needing repair or replacement.
- Fuel Injector Replacement - $400-$800 per injector on the direct injection system.
- O2 Sensor Replacement - $200-$400 including parts and labor.
Most P0172 fixes on the 2022 TLX cost between $150 and $450. Start with the cheapest diagnostic step: cleaning the MAF sensor.
Can You DIY This Repair?
MAF sensor cleaning is straightforward and takes minimal tools. Inspecting boost hose clamps is also doable at home. However, direct injection injector work and turbo system repairs require specialized knowledge and equipment. For those jobs, take your TLX to an Acura dealer or qualified independent shop.
Prevention Tips
- Replace the air filter at recommended intervals to keep the MAF sensor clean
- Use premium 91+ octane fuel as recommended by Acura
- Add fuel system cleaner every 10,000 miles to maintain injector health
- Have turbo system components inspected during regular service visits
- Do not ignore a check engine light, as a rich condition can damage the catalytic converter