code reader (help take off cap)

[5.0TailPipeHump]

Ok i got a code reader and found where to test it but i cant get the dam cover off to test it , i got a ford truck and had no problems getting that 1 off , how come i cant get this off, i just want to see if its throwing any codes my way. Is there a special way to do this. Also when testing sould i have the key in the on positon then begin testing . thankyous

 

[Hickfied]

Just pull the tabs away from the cap, and slide it off.

I have never owned a fox that had caps actually, only seen one fox ever that had it in place.