Casa Grande, AZ Noise Ordinances: Vehicle Noise (2026)

Section 9.24.030(A) of the Casa Grande Municipal Code makes it unlawful to repair, rebuild or test a motor vehicle in a residential area between 9:00 p.m. and 6:00 a.m. in a manner that creates excessive, unnecessary or offensive noise causing discomfort or annoyance to a reasonable person of normal sensitivity. Subsection B separately requires that any vehicle operated within the City have an exhaust system free from defects that could cause sound level magnification, equipped with a functioning muffler, and not modified to amplify or increase the sound level above what the factory-installed muffler emitted.

Subsection C prohibits the use of exhaust brakes, engine brakes, engine retarders or similar devices anywhere in the City, though it is an affirmative defense that the device was used in a bona fide emergency reasonably necessary to protect persons or property. This section sits within Chapter 9.24's broader noise scheme, which in Section 9.24.010 lists factors, including noise level, duration, time of day and proximity to sleeping facilities, that bear on whether conduct is unreasonable. As with the rest of the chapter, violations are treated as civil offenses enforced by the Casa Grande Police Department under Section 9.24.060, with escalated criminal treatment for habitual offenders.