P2173: Throttle Actuator Control System - High Air Flow Detected
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes, gently - the computer has noticed more air than the throttle should allow and may cap power. If idle surges high or the engine races, stop: that is unmetered air taking over.
Symptoms
- High or surging idle
- Reduced power mode
- Hissing under the hood
- Check engine light with throttle codes
Likely causes, most common first
- Vacuum leak after the throttle
- Intake boot cracked or clamp loose
- PCV or brake booster hose split
- Throttle body fault reporting less opening than real
Read P2173 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P2173 is the throttle system doing arithmetic and objecting: airflow into the engine exceeds what the throttle plate's angle can explain. Air is arriving around the throttle rather than through it - the definition of a vacuum leak - or the throttle is reporting less opening than it truly has.
The hunt is old-school and satisfying: cracked intake boots that only gape when the engine rocks, PCV hoses gone soft, booster lines split at the elbow, gaskets breathing at one corner. A shop's smoke machine finds in ten minutes what ears and carb cleaner find in thirty. The reason not to shrug this off indefinitely: unmetered air leans the mixture and raises idle, and a leak that grows can make the engine hold revs against your intent - the moment it does, the casual repair stops being casual.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P2173
“The contact owns a 2013 Dodge Avenger. The contact stated while driving 55 MPH the vehicle shut down completely and an unknown warning light illuminated. The vehicle was towed to an independent mechanic and the mechanic stated that the gasket was leaking and that an unknown gasket (P2173). The vehicle was repaired but the failure continued. The manufacturer was contacted, and the manufacturer was contacted, and no assist was provided. The failure mileage was 185,489.”2013 Dodge Avenger · Feb 2023 · 185,498 mi
“I purchased the vehicle 4 months ago, and this began at the end of September. Engine stalls out when driving down the highway, check engine light and road hazard lights come on and car trying to accelerate itself at times and other times won't go over 40 mph. If you let off the brake the car immediately launches forward. I have almost been hit as the car stalls out of no where. I can pull over and turn it off then back on and it will drive for a few miles then happen again. The car was hooked up to the code reader and it says throttle body injector P2173”2016 Jeep Patriot · Sep 2022
“While driving my Patriot, as I turned into the gas station the check engine light, traction control light and ETC (red lightning bolt) all popped on at the same time. My vehicle instantly went into limp mode. When In park, stayed a consistent 1,500 RPM's. All of this happened without warning as the car drove and ran like normal prior. Thankfully I was only .5 miles from home and was able to get it home. Code pulled: P2173 car has always been maintained on time since date of purchase.”2016 Jeep Patriot · Feb 2022
Show 1 more owner reports
“While driving at hwy. Speed vehicle surged but no warning lights, etc. Next time started, warning lights came on indicating a p2173 code.car was just at dodge dealer for recalls. Car will idle fine for a couple of minutes then start surging, idling rough with no power and set warning lights, mil, etc, esc. These will go off when vehicle is turned off except for check engine light. We have replaced throttle body with no change. Cleared code and came back and did the same. Very disappointed that dodge has not addressed this issue. It is not safe.”2013 Dodge Avenger · Dec 2019 · 91,000 mi
Cars that report P2173 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P2173?
Yes, gently - the computer has noticed more air than the throttle should allow and may cap power. If idle surges high or the engine races, stop: that is unmetered air taking over.
How much does it cost to fix P2173?
Typical US repair costs range from $20 for the simplest fix (hose and clamp repair) to $300 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P2173. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.