P0442 P0455 P0457 EVAP Leak Ford Mustang – Smoke Machine

2004 Ford Mustang EVAP Codes pulled with Genisys Scan Tool

Evaporative leak codes can be caused by broken fuel vapor lines, gas tank seals leaking, EVAP canister cracked, etc. EVAP codes can be some of the most difficult fault codes to diagnose. After pulling codes and checking the obvious by doing a quick visual inspection, to verify it’s not just a loose gas cap you’re dealing with. Bring out the smoke machine, it’s a great auto specialty tool that is really a necessity in any automotive repair shop today. In addition to checking for EVAP leaks, it can also be used to check vacuum leaks for lean codes and exhaust leaks that aren’t quite so easy to pinpoint.

EVAP Smoke testing helps pinpoint leaks quickly

The leak in the Evaporative system on this Mustang was right at the filler neck, where it goes into the tank. Smoke came pouring out immediately. The customer complained of gas smell also, so it made sense that it would most likely be caused by a rather large leak.

Filler neck seal at tank was cracked.

The filler neck seal at the tank pictured above had a huge crack, you can see the gaping hole. To replace it was easy. Remove the 8mm screw for the filler neck and loosen the 13mm bolts for the gas tank straps. The tank can then be lowered enough to pull the filler neck out. Remove the old seal and install the new one, paying attention to the placement of slot in the new seal. A little silicone spray for lubrication and the filler neck slipped back into place. If your shop doesn’t have a smoke machine it should, save time and make more money, here is a tech article with more info.