charcoal filter: check engine light?

[93SHO]

Hi guys, I am new to the forum and I am grateful for all of the useful info on the site. My dads 2001 boxster frequently has the check engine light come on and then goe off a few days later. He took it to a porsche mechanic who said it was the charcoal filter. he said it will cause no harm if he continues to drive but that eventually he will want to get it fixed. The shop wanted $400 dollars to replace it but after checking out the forum i found write-ups on replacing the filter, it seems super easy but before i start ripping apart my dad's boxster i wanted to check if this was acutally the problem: could a bad charcoal filter cause a CE light?
thanks for your help.