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Smoke Tester -- Ford Escape P0442 (small leak in Evap)

I got a code P0442 on my 2002 Ford Escape V6, which means there’s a small leak somewhere in the Evap system. As part of the procedure to fix this, there’s a TSB that describes the use of a smoke tester.

1) Is there a way around using a smoke tester to fix this? I.e., is there component/hose that commonly fails?

2) I’ve read about people using “fog machines” as their smoke tester. Would it be be safe for the car to go this route? A fog machine is $30, while a “real” smoke tester is $700 and up.

A potential place for "minor leak’ is the gas cap seal. Necissity is the mother of invention. I must commend you for thinking of another path to take rather than a full on smoke machine but perhaps biting the bullet (if only for diagnosis) may be the better way out of theis. I can’t see any harm (other than inconclusive results and time wasted) by using a fog machine. (I know I spelled necissity wrong)

Did you at least check out the gas cap as oldschool suggested? Clean the rim of the filler neck really well, feel it for irregularities. Clean the cap’s gasket - coat it with a bit of vasoline or something like that. Put it on clear the code and see what happens.

If that doesn’t help you can at least start with a visual inspection of your own. It is true that small leaks are hard (sometimes impossible) to find this way. But if you just locate the lines and inspect carefully you might get lucky. If these are just standard rubber or plastic vacuum lines you could probably just replace them for less than having a smoke test (if you were doing the replacing yourself). Vacuum line is very cheap. This is obviously most practical for those lines under the hood but I’d do that before I bought a smoke test.

I can’t say about the fog machine b/c I just don’t know.

You need the smoke tester for vehicles.

A disco fog machine doesn’t produce a high enough static pressure to detect a leak in the EVAP system on a vehicle.


I put a new gas cap in it. $11.

Problem solved (so far; I haven’t gone through a tank of gas with the new cap yet).

Thanks for all your responses.