Symptoms of a P0455 code

I have a 98 Taurus that has developed a hesitiation while driving. I also have a P0455 code. The hesitation often occurrs between 30 - 40 mph and occasionnally when accelerating from a dead stop. When it ocurrs, it feels like a clogged fuel line. My mechanic has looked at it, checked vacuum lines, we've changed the fuel cap, cleaned the MAP sensor and nothing has worked. The hesitation would stop for a few days, but come back. During the last visit the mechanic said he found where the insulation on a plug wire had been melted from laying against the dip stick tube. He believed that it was shorting out through this, causing the hesitation. He replaced it and kept it for to test it. As expected, the hesititation never happened again while at his shop. However, the hestation and code are both ocurring again.

2 Questions -
Does anyone have any suggestions to solve this problem?
The mechanic said that the hesitation and the code are not related. However they started happening at the same time. Any thought if they are related or not?

Thanks!!

P0455 - Evap emission control system leak detected.
A smoke test is uses to pin point leaks.
Symptoms - DTC, and you could probably smell gas.
Suspect: bad plastic, rubber, or seals

Would the hesitation be caused by the code? Also what it a DTC?

The P0455 Diagnostic Trouble Code (DTC) would not be likely to cause the hesitation. Are you absolutely certain the correct code you are getting is P0455.

-Rod

This hesitation is likely a vacuum leak problem. It could be coming from the intake manifold gaskets, throttle body, air filter housing or else. It could be intermittent, especially when engine temp change. Have a vacuum test at idle and if it's too low, a smoke/dye test or starter fluid test to find the leak at intake. And of course it's not related to code.