On the 98 Mark I came up with code P0001 which gave me fuel volume regulator and control circuit/open. It also gave me a 10 with a $....Does this code mean I have a bad regulator?....Whats with the control circuit/open....Need some help with these 2.....I also went into the I/M Readings and found: CAT had an X, Evap had an X and Air had an X....Now I'm probably wrong but do the Xs mean I have bad O2 sensors?.....AS you know I appreciate any and all advice....If someone could decipher these I will get them fixed. Thanks......Bruce L. Hansen.....Senior Citizen....Still living by the grace of God