Been hunting the cause of a persistent check engine light for a while. Finally got serious when the P0442 code for small evap system leak was joined by a P0455 large evap leak code that would appear within a day of getting cleared. Also noticed a whiff of fuel vapors from rear of car once in a while. Took off inspection covers for fuel pump area and the smell almost knocked me flat. Fuel pump assembly was leaking badly, to the point of leaving a small puddle of fuel on top of the tank. Since i could not unscrew the unit, I tried a last ditch effort and used fuel-resistant gasket maker to seal around the edges. Messy, but very cheap and effective (first image). P0455 and fuel smell went away, but the P0442 code stubbornly remained.
I built a smoke generator to aid in visualizing the leak. Soldering iron, inlet port, and outlet port attached to the lid of a glass jar with epoxy. A bundle of paper towels as a wick wrapped around the iron and extending to a pool of mineral oil at the bottom of the jar. I used a low power aquarium pump since it has a very low max pressure. (second image).
I unhooked the vent line to the fuel tank and plugged in the smoke generator. After a few minutes, I began to see very faint wisps of smoke near the fuel pump assembly, but a soaking of soapy water yielded no bubbles. The fuel sender is a separate unit right nearby, so I sprayed the soap there, and was rewarded by a stream of bubbles. Another application of the gasket maker and both bubbles and smoke stopped (third image). I thought I was done, so I cleared the codes and drove as normal for a while.
Alas, the P0442 just returned. Tomorrow the smoke machine comes out to play again, and I hope its a part I can replace or a crack I can plug with goop. I feel like I'm playing whack-a-mole here
I built a smoke generator to aid in visualizing the leak. Soldering iron, inlet port, and outlet port attached to the lid of a glass jar with epoxy. A bundle of paper towels as a wick wrapped around the iron and extending to a pool of mineral oil at the bottom of the jar. I used a low power aquarium pump since it has a very low max pressure. (second image).
I unhooked the vent line to the fuel tank and plugged in the smoke generator. After a few minutes, I began to see very faint wisps of smoke near the fuel pump assembly, but a soaking of soapy water yielded no bubbles. The fuel sender is a separate unit right nearby, so I sprayed the soap there, and was rewarded by a stream of bubbles. Another application of the gasket maker and both bubbles and smoke stopped (third image). I thought I was done, so I cleared the codes and drove as normal for a while.
Alas, the P0442 just returned. Tomorrow the smoke machine comes out to play again, and I hope its a part I can replace or a crack I can plug with goop. I feel like I'm playing whack-a-mole here