Check engine light smoke test

CALIMAN316

MEMBER
2006 TOYOTA CAMRY
3.3L
V6
AUTOMATIC
99,200 MILES

Hi. I had my check engine light turn on so I went to AutoZone and they check that the code was a P0442. So I changed the gas cap and that didn't work. So I went to Toyota and they did a smoke test which they saw nothing was wrong and it passed but the check engine light still showed up. They said that they could not find the problem, so they recommended that the valve set and hoses need to be replaced, but cannot guarantee that will the check engine light may show up again. If does the other alternative would be to replace the charcoal canister which may have an internal leak which could be very small. The price of changing the valve set would be $716.00 and to replace the canister would be $930.00. I paid $80.00 for the smoke test. My concern is what if neither these fixes the problem, it is either one or the other or both. One of them also said that when I fill my gas, once it clicks do not fill anymore which could help as well. My engine light is on but I have it erased with a obd2 scanner. Can you please advise, if I pass the smoke test why do I still have the light come one here and there?

2 Replies

SATURNTECH9

MECHANIC
30,869 POSTS

You could have a intermittent evap leak that is one explanation. Also, when they did the smoke test did they also do a nitrogen flow gauge test? That is where they seal the evap system and pump in nitrogen and what a flow gauge on the nitrogen cart and they can see if there is a leak at the time. Another method is seal the system and pump in nitrogen and use a ultrasonic leak detector to hear the leak. Also, there may have been a leak but they just did not see the smoke because it was up on top of the fuel tank etc, where it was easily visible. But you can use a inspection camera to find a leak like that.