
Many generations of different car models have their common problems that owners run into. Here are the most common Toyota Matrix problems of the 1st generation, years 2003 to 2008.
Top 5 1st Gen Toyota Matrix Problems (2003 to 2008)
1. MAF Sensor Failure
Symptoms of a Faulty MAF Sensor
A bad mass air flow (MAF) sensor can cause problems with the engine and transmission on the 1st gen Matrix, like:
- Lack of engine power
- Rough running engine
- Problems shifting
- Check engine light for code P0171
How to Fix a Faulty MAF Sensor
- Before replacing the MAF sensor, check the hoses for rips or tears
- Listen for air leaks at the intake gasket
- Clean the MAF sensor with MAF sensor cleaner
2. Loose/Unsecure/Falling Windows
Symptoms of Loose Windows
- Windows are loose and fall into the door
- Rattling sounds from inside the door
Causes of Window Problems on the 2003 to 2008 Toyota Matrix
The screws that hold the window glass to the window regulator can loosen over time and loosen up the window.
How to Fix Loose Windows
Steps for fixing a falling window
- Remove the Door Panel
Remove any trim panel covers, screws, clips, and switches from the door panel, and then loosen and remove the door panel to access the window.
- Tighten the Loose Screws
If the window screws are loose, tighten them. To secure them tightly, go to step 3.
- Secure the Window with Painter’ Tape
Loosen the screws from the window, raise the window up and out from the door, and secure it in place in the window frame with painter’s tape.
- Reinstall the Screws with Thread Locker
Apply thread locker to the screws to help secure them long-term and tighten the screws back to the window.
3. EVAP Codes
Causes of EVAP Codes
If your check engine light turns on and the scan tool reads for an EVAP code, check the gas cap first. If the code is related to the gas cap, the EVAP canister is usually leaking on the 03-08 Matrix and catches fuel vapors so they don’t enter the atmosphere
How to Fix EVAP Codes
First, follow these steps to check the gas cap
- Pull the gas cap back and straight out, checking for looseness
- Check the gas cap gasket for torn or broken pieces
- Tighten the gas cap and check its ratcheting ability
To replace the EVAP canister, steps include disconnecting the electrical connector, removing the bolts, and removing the canister. Reverse these steps to reinstall the canister.

4. Catalytic Convertor Failure
Symptoms of a Faulty Catalytic Convertor
- Lack of engine power
- Slow acceleration
- Check engine light for code P0420
Causes of Catalytic Convertor Failure on the 2003 to 2008 Toyota Matrix
The catalytic convertors tend to fail on the 2003 to 2008 Toyota Matrix, causing a check engine light or engine performance problems.
How to Prevent Catalytic Convertor Failure
If the catalytic convertor is faulty, it needs to be replaced.
To help prevent catalytic convertor failure, change the spark plugs, air filter, and oil regularly according to the recommended intervals in the owner’s manual.
5. Bad Engine and Transmission Mounts
Symptoms of Bad Engine and Transmission Mounts
- Clunking noise when shifting in and out of different gears
- Excessive vibrations when in gear, like when sitting at a stop sign
Causes of Bad Motor Mounts on the 1st Gen Toyota Matrix
These engines tend to vibrate in general, which can loosen the engine mounts over time. Excessive vibrations indicate there is probably a problem with the motor mounts.
How to Fix Engine Mounts
Replacing the engine mounts is not an easy job for inexperienced mechanics.
The engine mount is located at the front of the vehicle and at the front of the engine. A transmission mount is located behind the battery/underneath the air filter, and another transmission mount is located at the backside of the transmission and close to the firewall.
Fix Your Own 1st Gen Toyota Matrix
Save on parts and repairs. Fix your own 2003 to 2008 Toyota Matrix with many how-to videos in 1A Auto’s video library for this generation, such as control arms, headlights, axles, struts, brakes, and more.
Shop 1st Gen Toyota Matrix Parts
Related Content
- P0420 and P0430 codes: Diagnose and fix like a mechanic [how-to guide + videos]
- How to Fix P0171 Code
- How to Test a MAF Sensor
- Gas Cap Throwing a Check Engine Light? [Diagnose & Fix]
- What are the Symptoms of Bad Motor Mounts?
- Front End Clunking Noise While Driving?
- What Does a Window Regulator Do?
1st Generation Toyota Matrix Model Years
- 2003 Toyota Matrix
- 2004 Toyota Matrix
- 2005 Toyota Matrix
- 2006 Toyota Matrix
- 2007 Toyota Matrix
- 2008 Toyota Matrix

