CADILLAC STS INSTRUMENT CLUSTER GAUGES SPEEDOMETER

I Have A 2001 Cadillac Sts. It Has A Interlock System Installed. I Have Replaced The Vss And Problem Is Still Present. Code P0604 Is Showing...

A Few Days Ago I Let A Friend Drive He Put Diesel Fuel In Instead Of Premium I Was Told To Pour Sea Foam In Tank And Let It Flush Out Since...

I Was Driving When My Speedometer Dropped To 0 And My Car Began Jerking Forward. Everything Works Normal In Reverse. No Codes Came Up On...