My roadster required me to do several throttle resets, the coupe didn't require any...go figure....but, if there was a check engine light, code, thrown for low voltage on the throttle, then obviously the sprint booster was bad....and I have never heard of this company...I ordered direct from the factory on the roadster...no so on the coupe...bought from a forum member...either way, it should make a difference...so maybe the second one will work...SRT SIX is a trusted dealer if the second doesn't work...get you selectable one from him...