I have a 1997 Plymouth Grand Voyager with a 3.0 V6 and 129,000 miles on it. Recently the service engine soon light came on. I scanned it and the code “emissions leak” appeared. I re-tightened gas cap and cleared code. I have done this a couple of time and after a day or two the service eng. soon light reappears. Any clue what could be causing this?
I think we had one of those with the same problem. It ended up in ours there is a pump that pressurizes the system for the check, and the pump failed.
Give us the real code number. There are a variety from small/slight EVAP:PURGE leak to MAJOR EVAP:PURGE leak to failure of the pump circuit.
Just because you tightened your cap, don’t assume that it’s good. Both my jeep caps failed and they were relatively NEW.
Geeaea is right. there are some 20 different fault codes just for the EVAP system. Having the correct one(s) could help us help you.
Generally, what causes the EVAP system light to come on is an air, or vacuum, leak in the gas tank, its fill tube, or the vapor lines between the gas tank and the engine.
After some years, rubber hoses and seals deteriorate. When they do, they can leak. A detectable leak is very small—the size of a pin hole.
What can you do before you turn the problem over to a mechanic? You can examine the hoses between the gas tank and the charcoal canister, and from the charcoal canister to the engine intake manifold. If you see any deterioration, especially at the ends of the hoses, replace the hose, or cut off the bad end (if the length is long enough).
Often, the EVAP system will perform its self-test only if the gas tank is between 1/4 and 3/4 filled. It may take several drive trips before everything is ready for the self-test to run. This is why the trouble light may not come on for several days, when there is a problem.