EVAP Smoke Test

A smoke test is one of the most effective methods for locating leaks in the EVAP system and the engine intake system. During this test, a special non-toxic smoke is introduced into the system under low pressure. If a leak is present, the smoke escapes from the exact location of the problem, making it easy to identify the source of the leak. This test helps detect damaged hoses, cracked vapor lines, loose connections, or faulty EVAP valves. Smoke testing is also commonly used to find vacuum leaks in the engine intake system, which can cause rough engine operation, Check Engine lights, or misfire conditions. In many real-world cases, leaks appear after previous repairs when connections were not tightened properly or seals were not installed correctly. A smoke test allows technicians to quickly locate these types of issues. The typical cost of this diagnostic test at our shop is around $150 and it helps pinpoint leaks without unnecessary disassembly.