| Business | Phone |
| M & N Auto Svc 1235 Parkside Dr, Walnut Creek 94596 | (925) 256-9500 |
| Contra Costa Smog 1411 Autocenter Dr, Walnut Creek 94597 | (925) 947-2555 |
| Gic Smog Check 690 Ygnacio Valley Rd, Walnut Creek 94596 | (925) 938-5752 |
| Gordon's Smog Test & Lube Center 1506 3rd Ave, Walnut Creek 94597 | (925) 947-6068 |