I have a 1999 Dodge Caravan it's a 2.4 l I recently did a tune-up on it and it was ruuning beautifully 2 weeks later now when i slightly accerate it acts like its in too high of a gear like shuddering tried manually shifting seams to work have read maybe speed sensor it does not do it every time but most times want to solve this soon cause its only got 70000 miles and is in nice condition plz help