On my 98GT, I'm having a problem with my tachometer. When I slow down to idle, (ie. red light, stop sign, restaurant drive-through), the needle will act as if it's slipping and drops down to 250rpms or even less than 100. When you tap the gas gently, you can see the needle kinda "jump" back to where it's supposed to be and then it will slowly do it again. The car is idling fine even when the needle is showing to be at almost zero, just the needle is acting up. I have previously installed white faced guages in the car but the guages have acted flawless for almost 8 years since I put them in. What would be causing this?? I'm assuming some sensor gone bad, but not for sure. Thanks for any help in advance!
