Can you modify a Toyota Avalon?

You can modify a Toyota Avalon, but what’s feasible and advisable depends on the model year, drivetrain (gasoline or hybrid), and local rules; some changes are safe and reversible, while others can affect warranty, emissions compliance, and insurance.

The Avalon—Toyota’s full-size sedan that was kept in the lineup in the U.S. through the 2022 model year before being superseded by newer designs—continues to attract owners who want more style, better handling, or enhanced tech. Because it’s no longer in active production for most markets, modification options vary by generation, parts availability, and compatibility with hybrid systems. This guide outlines practical paths for customization, plus important caveats to keep you on the right side of warranty, law, and safety.

What you can modify on a Toyota Avalon

Owners typically start with cosmetics and convenience, then move to handling and power as desired. The list below groups common modification avenues to consider.

• Cosmetic and exterior tweaks: aftermarket wheels, tires, window tint, paint wraps, daytime running lights, and cosmetic trim pieces.


• Exterior aerodynamics and lighting: spoilers, diffusers, upgraded headlights or taillights, and smoked or clear lens accents.


• Interior and infotainment: upgraded audio systems, navigation or head-unit swaps, USB/charging extensions, and improved sound insulation.


• Suspension and handling: lowered springs, coilovers, sport sway bars, and bushings to tighten ride and reduce body roll (note: ride comfort may change).


• Brakes and tires: performance brake pads, slotted rotors, high-performance tires, and improved brake fluid; always ensure proper sizing and clearance.


• Powertrain and exhaust (varies by model): cat-back or turbo exhaust options, intake upgrades, and engine tuning. Hybrids require extra caution to avoid interfering with battery cooling and hybrid control software.


• Electrical performance and safety systems: modifications to airbags or sensor systems are strongly discouraged; instead focus on non-critical electronics enhancements or OEM-recommended accessories.

Modifications like wheels, suspension changes, or a new exhaust can dramatically alter handling, noise, and fuel economy. Always prioritize parts that fit your exact Avalon generation and trim, and consider professional installation to ensure proper clearance and safety.

Important considerations before you modify

1. Warranty and dealership policy: Modifications can void or limit coverage, particularly if the item or its installation is not OEM or not approved by Toyota. Using Genuine Accessories or dealer-installed options can mitigate some risk.


2. Legal and emissions compliance: Exhaust, intake, or ECU changes can affect emissions tests and noise regulations in your region. Some jurisdictions require inspections that may fail if the car is too modified.


3. Insurance implications: Most insurers treat modifications as a risk factor, potentially raising premiums or altering coverage. Always inform your insurer and keep documentation.


4. Reliability and safety: Inadequate or improper installs can compromise braking, steering, or airbag systems. Use reputable shops with experience on Toyotas and hybrids when applicable.


5. Resale value and ownership practicality: Some buyers prefer stock vehicles; highly personalized builds may limit resale options. Consider reversible or easily removable mods and keep stock parts for resale.


6. Parts availability and service: The Avalon’s discontinuation means some aftermarket options and OEM parts may become scarce over time. Verify fitment and source support for your specific year and trim.

These considerations help weigh the upside of a modification project against potential drawbacks in warranty, legality, and long-term ownership costs.

Where to start and how to do it safely

1. Define your goals: decide whether you want cosmetic upgrades, improved handling, or modest performance gains, and set a realistic budget.


2. Confirm model-year compatibility: confirm that parts and upgrades are designed for your Avalon’s generation and trim (gasoline V6 vs. hybrid).


3. Consult reputable sources: explore Genuine Toyota Accessories, TRD options if available for your generation, and trusted aftermarket brands with a track record for Toyota compatibility.


4. Choose a qualified installer: use a shop with explicit experience with Toyota vehicles and, if applicable, hybrid systems. Get written quotes and warranty terms for the installation.


5. Document and preserve stock parts: keep the original components so they can be reinstalled for resale or warranty considerations.


6. Test carefully and monitor: after installation, perform a cautious test drive, monitor for unusual noises or warning lights, and verify reliability over time.

Maintaining safety and legality for a modified Avalon

Safety should be the top priority. Ensure that any modification does not interfere with the vehicle’s safety systems, Sensor suites, or crash structures. Respect local noise, exhaust, and emissions laws, and maintain compliance with vehicle inspections where required. A well-planned modification strategy that emphasizes professional installation, reputable parts, and full disclosure to your insurer will reduce risk.

Alternative paths if you want modern tech or performance

If you’re seeking the latest tech or higher performance without extensive customization, consider:

• OEM-verified tech upgrades and retrofit options offered by Toyota or certified dealers for your generation.


• Professional infotainment upgrades that preserve steering-wheel controls and steering-column integration.


• High-quality tires and braking components that improve performance while staying within warranty and legality bounds.


• Performance-focused driving schools or tune-up services that emphasize safe, reversible improvements without altering core systems.

Summary

Modifying a Toyota Avalon is feasible and can be rewarding, but it requires careful planning. The right approach depends on your exact model year, whether you have a gasoline or hybrid variant, and how you balance aesthetics, handling, and reliability. Prioritize official accessories or trusted, generation-specific parts, work with qualified technicians, and stay mindful of warranty, emissions, and insurance considerations. With a thoughtful plan, you can tailor an Avalon to fit your style while keeping safety and legality front and center.

What is the common problem of Toyota Avalon?

Common problems for the Toyota Avalon include ignition coil failures, especially after 100,000 miles, and leaking valve cover gaskets. Other issues include problems with the automatic transmission, such as rough shifting, and issues with the Evaporative Emission Control System (EVAP) (like a faulty canister or purge valve) which can cause a check engine light. Some model years have also reported specific issues like unintended acceleration and peeling paint.
 
This video discusses some of the common problems found in Toyota Avalons, including the engine and ignition coils: 56sSimple Mechanic AdviceYouTube · Nov 3, 2024
Engine 

• Ignition Coils: May fail after 100,000 miles, leading to misfires and a check engine light.
• Oil Leaks: Valve cover gaskets are a common source of oil leaks.
• EVAP System: Issues with the EVAP canister or purge control valve can trigger the check engine light.
• Oxygen Sensor: A failed oxygen sensor can cause the check engine light to turn on.
• Sludge Buildup: Can occur with infrequent oil changes and cause engine problems. 

Drivetrain and transmission

• Automatic Transmission: Some owners report the transmission not shifting correctly at higher mileages. 
• Unintended Acceleration: A serious problem reported in some models, particularly the 2014 model year, where the gas pedal may become stuck. 

Other common issues

• Rear Window Sunshade: This feature has been reported to fail and make a grinding noise. 
• Peeling Paint: A problem reported on certain model years, often on the roof and around the sunroof. 
• Infotainment System: Some owners have complained about distorted speakers and issues with the infotainment system. 

This video provides a buyer's guide for the 2013-2018 Toyota Avalon, including information on reliability and common problems: 59sDiscerning CarsYouTube · Dec 16, 2023

Which is faster, Avalon or Camry?

The Toyota Avalon typically offers a more powerful engine lineup compared to the Camry, including V6 and hybrid powertrains that deliver impressive performance and fuel efficiency.

Is the Toyota Avalon powerful?

Autotrader (2021)
"With a potent 301-horsepower V6 mated to a smooth-shifting transmission, the Avalon has good power to get up and go."

What year to stay away from Toyota Avalon?

Years to potentially avoid for the Toyota Avalon include 2005–2007, which had common issues like oil leaks and dashboard cracking, and the 2013-2014 models, due to a high number of Technical Service Bulletins (TSBs) and problems like the pre-collision system causing unexpected braking and a risk of the ball joint detaching. The 2011 model year is also mentioned for its high number of owner-reported issues. 
Years to be cautious with

• 2005-2007: This third-generation group is associated with several problems, including: 
  • Engine oil leaks and excessive oil consumption 
  • Cracked dashboards 
  • Faulty VVTi oil lines that can cause engine damage 
  • Transmission hesitations 
• 2011: Known for significant peeling paint on the roof. 
• 2013-2014: These models from the fourth generation had a notable number of issues, making them a riskier purchase. 
  • The 2013 model had a high number of TSBs and was described as a "big risk" by some users, according to this YouTube video. 
  • The 2014 model year is associated with issues like:
    • Unexpected braking due to the pre-collision system 
    • A risk of the ball joint detaching from the lower control arm 
    • Potential fuel leaks 
• 2014: Owners reported issues with the suspension and touchscreen, including poor Bluetooth connectivity. 

Why these years are a concern

• Fourth generation redesign: The 2013-2018 redesign made some significant changes, and the initial years (2013-2014) struggled with settling on a reliable platform, resulting in numerous recalls, TSBs, and reported issues. The 2015 model year is noted for having far fewer issues, according to this YouTube video. 
• Common issues: Many of the issues reported across the third and fourth generations were related to minor component failures, such as the rear sunshade or door lock actuators, but some were more serious, like unexpected braking or potential fuel leaks.