Pontiac Grand Am Engine Surge

While Driving Slowly As In A Parking Lot, If I Let The Rpm's Go Down To 500, The Engine Will Surge Up To 800. While It Is Only A Short...

It Runs Great Highway Speed Until I Step On The Gas To Pass And The Engine Surges Up And Down. I Replaced The Fuel Filter To Start. Not...

So This Problem Just Started After We Basically Combined Two Of The Same Cars Into One, Lol. No Problems Upon Starting And Runs Fine Right...