393.83C — Improper exhaust - Bus (Powered by gasoline)
FMCSA violation code under Vehicle Maintenance. 8 events recorded in roadside inspections. Severity weight: N/A.
Violation Description
Improper exhaust - Bus (Powered by gasoline)
About This Violation Code
Code 393.83C falls under the Vehicle Maintenance BASIC category in FMCSA's Safety Measurement System (SMS).
When this violation is cited during a roadside inspection, it contributes to the carrier's Vehicle Maintenance BASIC score. Carriers with high BASIC percentiles may be prioritized for FMCSA interventions including warning letters, investigations, or compliance reviews.
Regulatory Reference
Federal Motor Carrier Safety Regulations
This violation references 49 CFR 393.83C in the Federal Motor Carrier Safety Regulations.
Top Enforcing States
Where 393.83C is most commonly cited (last 180 days)
Click a state to see roadside inspection activity, top stations, and carrier profiles in that jurisdiction.
Citation Trend (12 months)
Monthly count of 393.83C citations. Red bars mark months with OOS-triggering citations.
Top Carriers Cited
Ranked by frequency • 7 carriers total
Top Carriers with 393.83C Violations
| # | Carrier | USDOT | # Violations |
|---|---|---|---|
| #1 | RURAL TRANSIT ENTERPRISES COORDINATED INC | 691393 | 2 |
| #2 | SHARP HEALTHCARE | 2626668 | 1 |
| #3 | SJL TRANSPORTATION LLC | 3018884 | 1 |
| #4 | ECHO WINDY CITY LLC | 4157925 | 1 |
| #5 | C 9 TRANSPORTATION INC | 3114285 | 1 |
| #6 | FIRST STUDENT INC | 354406 | 1 |
| #7 | BUS PARTY OKOBOJI LLC | 4406692 | 1 |
Recent Inspections
Latest inspections where 393.83C was cited • 8 total events
Recent Inspections with 393.83C
| Date | Report # | State | Level | OOS |
|---|---|---|---|---|
| Feb 4, 2026 | 86979036 | IL | Level 5 | Yes |
| Nov 26, 2025 | 86443227 | IA | Level 5 | Yes |
| Jul 17, 2025 | 85363178 | TX | Level 1 | Yes |
| Apr 16, 2025 | 84416817 | KY | Level 1 | Yes |
| Dec 16, 2024 | 83401911 | KY | Level 1 | Yes |
| Nov 8, 2024 | 83157676 | PA | Level 1 | Yes |
| Oct 23, 2024 | 82978791 | NE | Level 5 | Yes |
| May 29, 2024 | 82980491 | CA | Level 5 | Yes |