What 393.83(f) means in plain language
This citation means an inspector found your exhaust system held together with temporary measures—tape, wrap, clamps, patches, or similar quick fixes—rather than a proper repair. The regulation requires exhaust components to be fixed permanently, not patched.
Temporary repairs are a short-term band-aid. They don't address the underlying damage, they fail under heat and vibration, and they can leak exhaust gases or debris onto the roadway. The requirement is straightforward: if your exhaust is broken, it gets repaired the right way, not wrapped.
What our enforcement data actually shows
Across our 13 million inspection records, 393.83(f) has generated 694 citations all-time, placing it at rank #818 out of 3,036 FMCSR codes by volume. In the last 12 months and last 90 days, we recorded zero citations for this violation.
The out-of-service rate for 393.83(f) is 0.4%—meaning only 3 vehicles out of 691 cited were actually placed out of service. This is dramatically lower than the all-FMCSR average OOS rate of 31.4%. Inspectors treat this as a citation-and-repair issue in nearly all cases, not an immediate roadside removal.
Who gets cited most
Our enforcement data shows carriers operating primarily in cross-border and regional freight lanes receive the majority of 393.83(f) citations. The carrier with the most citations in our records is Ruben Carlos Trevino Sanchez (USDOT 1649689), with 9 citations, followed by Edelmiro Melendez Herebia (USDOT 2258), with 7 citations. These patterns reflect the geographic and operational footprint where these violations are most frequently detected.
Freightliner-brand trucks dominate the citation list, with 81 citations across our database. Kenworth (42), and vehicles in the "Other" category (35) also appear frequently. This likely reflects the prevalence of those makes in the fleets most often cited for exhaust issues, not a defect inherent to any single manufacturer.
How severe is this compared to similar codes
393.83(f) sits in a low-severity tier within vehicle maintenance violations. For comparison:
- 393.9(a) — Inoperable required lamps has been cited 660,737 times with a 15.4% OOS rate. Lighting failures occur far more often and are deemed serious enough to ground vehicles roughly 1 in 7 times.
- 396.3(a)(1) — Inspection/repair/maintenance (general) accounts for 236,919 citations with a 45.3% OOS rate, indicating systemic maintenance lapses that inspectors treat as critical safety issues.
- 396.17(c) — No proof of periodic inspection has 198,331 citations but a 0.0% OOS rate, mirroring 393.83(f): documentation and minor repair-method issues rarely result in roadside removal.
Your citation places you in the "repair and proceed" category, not the "unsafe to operate" category.
How to avoid it
Before every trip:
- Walk around the undercarriage and listen. A functioning exhaust system should be silent (aside from normal engine noise). If you hear rattling, hissing, or see debris, you have a problem. Do not wrap it; report it for repair.
- Check for visible damage. Look for bent, cracked, or hanging pipes, mufflers, and heat shields. Temporary repairs with tape, wire, or clamps will fail within hours of highway driving. Get metal-to-metal welds or bolt-on replacement parts instead.
- Feel for heat leaks. If you notice unusual heat radiating from the underside near the fuel tank or frame, your exhaust is compromised. This is a fire hazard and a citation waiting to happen.
- Inspect brackets and hangers. Loose or broken hangers cause pipes to sag and rattle. These are cheap to replace and prevent both exhaust citations and secondary damage.
- Know your vehicle make. Frieghtliners and Kenworths in our data account for the bulk of these citations, but that reflects deployment, not design. Regardless of make, commit to permanent repairs only.
If you're already cited:
You likely will not be placed out of service. Plan a repair stop at a qualified shop within your next 24–48 hours. Document the repair with an invoice. Inspectors understand that temporary field fixes happen; they want to see them resolved, not repeated.