BORLA 140121 Cat-Back Performance Exhaust System for 2004-2009 Mazda 3 Sedan/Hatch 2.3L 4 Cyl. Automatic/Manual Transmission Rear Wheel Drive 4/5

The Borla 140121 Cat-Back Exhaust System has received mostly positive reviews from customers. Users have praised the sound quality of the exhaust system, noting that it has a nice growl at start up and in the lower RPM range. The high-end sound is also good, though some customers mentioned that the sound of their KN intake is louder than the exhaust. The exhaust system has been described as not being overbearing and not interfering with conversation inside the car. However, one common complaint about the product is the installation process. Customers have mentioned that it can be a bit labor-intensive and challenging, especially compared to other exhaust systems they have installed in the past. The installation involves hacking the exhaust in two locations, and fitting the new system can be a wrestle. However, once installed, it clears everything nicely and perfectly fits the bumper. Overall, customers are satisfied with the Borla 140121 Cat-Back Exhaust System due to its excellent sound quality and minimal interference inside the car. The installation process may be challenging, but the end result is worth it for many customers.