I'm getting code 45 now anyone know how to fix this one .Still backfiring too

 

I'm still getting ticking noise from motor too.I thought maybe exhaust but can't find leak thanks for any help

 

I just looked, and a code 45 appears to be the Barometric Pressure Sensor: Circuit Low Input

As far as what that means I have no clue

 

Could be t-bap sensor wire harness. Common problem. Going throuhg it right now for the second time. Wire breaks inside the insulation right before the connector or in the connector itself. Do a search for threads on T-Bap sensor for more info.
Good luck