Our 2002 Mecury Sable keeps jerking when stopped and sometimes jerks when first...

[fdamato75]

...acceleration ? We have taken it to the shop and they can only find spark plugs that are bad. All the plugs were replaced and a week after its been out of the shop it's jerking again. After awhile the check engine light will come on. It jerks to the point where it feels like it's going to stall and when you give it gas it sputters. Please help cause the mercury/lincoln dealer we take it too can't fix it.