A Guide to the 2014-2020 Chevrolet Impala Fuel Injection Throttle Body
Experiencing reduced power or a rough idle? Your Impala's throttle body might be the cause.
- A "Reduced Engine Power" message is the most common sign of a throttle body problem on a 2014-2020 Impala.
- Diagnostic code P2135 is strongly linked to throttle body failure but can also indicate pedal sensor or wiring issues.
- A throttle relearn procedure is mandatory after replacement to avoid high or unstable idle.
- For reliability, ACDelco is the top aftermarket choice, as it is the original GM parts supplier.
Is Your Impala's Throttle Body Failing?
A failing throttle body in the 2014-2020 Chevrolet Impala often doesn't fail suddenly. It usually starts with small, annoying issues that get worse over time. The most common complaint is a "Reduced Engine Power" message on the dashboard, which the car's computer triggers to prevent damage when it detects a problem. This limp mode is a clear sign that something is wrong with the air and fuel delivery system. You might also notice a rough or unstable idle, where the car shakes or the RPMs fluctuate at a stop. Other signs include hesitation when you accelerate, poor or sluggish acceleration, and the Check Engine Light coming on.
🎬 Watch this guide on common bad throttle body warning signs.Known Issues and Technical Service Bulletins (TSBs)
While no major recalls exist specifically for the throttle body on the 2014-2020 Impala, General Motors has issued technical service bulletins (TSBs) for related issues. TSB 11-06-04-007B, for example, addresses the common P2135 diagnostic trouble code ("Throttle Position Sensor 1-2 Correlation"). This code is a very common reason for the "Reduced Engine Power" light. The TSB suggests that in many cases, the sensor or its wiring is the problem, not the entire throttle body assembly. In colder climates, throttle body icing can also be an issue, leading to starting problems or stalling, as addressed in other GM bulletins.
Choosing the Right Aftermarket Throttle Body
When it's time to replace your Impala's throttle body, you have several options. The choice between OEM and aftermarket depends on your budget and quality expectations.
- Premium Aftermarket (ACDelco, Standard Ignition): ACDelco is GM's official parts brand, so their aftermarket parts are often identical to the original factory part. They are considered a top-tier choice for fit and reliability. Standard Ignition (SMP) is another well-regarded brand that manufactures new, not remanufactured, throttle bodies.
- Standard Aftermarket (Dorman, Cardone): Dorman is a popular aftermarket brand known for re-engineering parts to fix common OEM flaws. Their quality can be very good. Cardone offers both new and remanufactured parts; while they are a budget-friendly option, some mechanics report mixed experiences with their remanufactured electronics.
- Budget-Friendly Options (Global Parts, Store Brands): These offer the lowest price point but may have a higher risk of defects or shorter lifespan compared to premium brands.
Pro Tip: Clean or Replace?
Sometimes, symptoms like a sticky gas pedal or rough idle are caused by carbon buildup inside the throttle body bore and on the throttle plate. Cleaning it with a dedicated throttle body cleaner can sometimes restore function and save you the cost of a new part. However, if the electronic sensors are failing or the internal gears are worn, cleaning won't help and replacement is necessary.
🎬 See how to clean the throttle body on a 2.5L Impala.Cost of Replacing a Chevrolet Impala Throttle Body
The cost can vary significantly based on the part you choose and who does the work. The replacement itself is straightforward for a DIYer with basic tools.
| Part Type | Estimated Cost |
|---|---|
| New OEM (Dealer) | $350 - $500+ |
| New Aftermarket | $147 - $323 |
| Remanufactured | $100 - $200 |
| Shop Labor | $100 - $200 |
Frequently Asked Questions
Is a "throttle relearn" procedure required after replacement?
Yes. After installing a new throttle body, the engine's computer must relearn the new part's closed and open positions. Often, this can be done without a special tool by following a specific sequence of turning the ignition on and off and letting the engine idle. If this procedure is skipped, you may experience a high or erratic idle.
Can I replace just the throttle position sensor (TPS)?
On many modern throttle bodies, the TPS is integrated into the unit and cannot be replaced separately. Some GM TSBs do involve replacing just the sensor cover assembly, but this is a more complex repair. For most DIY mechanics, replacing the entire throttle body assembly is the simpler and more reliable repair.
What is the difference between the 2.5L and 3.6L throttle bodies?
The 2.5L 4-cylinder and 3.6L V6 engines used in the 2014-2020 Impala use different throttle body part numbers. They are not interchangeable. Always verify the part fits your specific engine before ordering.
Will a new throttle body fix my P2135 code?
Often, yes. The P2135 code indicates a disagreement between the two throttle position sensors inside the unit. This is a very common failure mode that a new throttle body will fix. However, the code can also be caused by a bad accelerator pedal position sensor or wiring issues, so proper diagnosis is key.
🎬 Learn how to fix Reduced Engine Power and P2135 codes.Helpful Videos
Technical Specifications
OEM Part Numbers: 12670839 12627217 12632172 12670981
The throttle body for the 2014-2020 Impala is an electronically actuated unit with an integrated throttle position sensor. It typically has a 6-pin electrical connector. The specific part number and bore size differ between the 2.5L LCV 4-cylinder engine and the 3.6L LFX V6 engine.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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