can someone tell me how to post a question, looks like same problem as guy below has. got issues with my vl symtomatic of the air sensor on the air filter box but code 14 (speed sensor) coming up. had this problem three or four times over the last two years but it seems to sort itself out after a few days of use. runs rough, trouble to keep it idling and gas usage through the roof. what is the speed circuit anyway, whats it do and how do problems manifest themselves?