I have always had an issue with the diagnosis of EVAP problems.

If anyone has any input, please post it,
Other then smoke machine is there any good way to test EVAP problems?
75% Of cars HAVE EVAP PROBLEMS, it is, i must say.. a VERY ANNOYING THING

[quote=rwdbmwm3]I have always had an issue with the diagnosis of EVAP problems.

the evaporator has a simple troubleshooting test..how much does the air temp drop after passing thru the evap...

this if not 25 deg f approx means that the a/c system needs pressure testing at the low/high sides...

another method is to measure the temp of the evap piping in/out and compare this difference is called superheat...usually just a few degrees different..

blockages in the refrigerant system will also cause a evap problem...
the evap may also have a large amount of debris blocking air flow then the evap will freeze into a solid ice block...

evap foul odors this is organic material decaying in the air box at evap..

the reason you and others have problems with this is because on most vehicles its not accessible...

you can't just give it a 5min look and come up with a repair cost...

j cAT, you're referring to the evaporator core. EVAP is the acronym/shorthand for Evaporative Emissions, which is what the original poster is referring to.

-rod

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j cAT, you're referring to the evaporator core. EVAP is the acronym/shorthand for Evaporative Emissions, which is what the original poster is referring to.

-rod

thanks for that clarification..
the fuel evap system can be complicated by the fact that this control is not standard so to troubleshoot you need specific info on how this is accomplished on each vehicle..

my findings have found the filler neck and lines on older vehicle to give these issues...control valves and the cannister are other areas of failure ..this is where I use the vehicle DTC to narrow down and test for failure be it electrical or mechanical...

all this does take time and cost can be substantial...