When I'm driving though the gear its not a back fire but like a thump it sounds like air throught the exaughst I had a fully built crower head and tune but it was put on by some one else could this be my injectors to big to small please help

 

I noe have a stock head btw
And a stock basemap on a p28 ecu obd 1

 

I have one

 

Lol I don't need one I have one on their and its doing what I deascribed up top

 

Tttt

 

Bump

 

Ttt

 

Yeah you need to be a little more specific about the situation. Also try using a little better grammer to better understand the issue.

 

Second gear the car spudders like a back fire but it is not a back fire it is sort of missing I replaced wires and spark plugs but it still doing it car also has arraticx idle it idles at 1500 then after a min it settles at 1000

 

my b18b1 idles at 1500 then will go down to 1000 also..i dont think that has anything to do with the backfire noise you are hearing...are you boosting or anything...it could be that you are just over loading like a b**ch