4.3 GMC Sierra engine
May 29th, 2022
4.3 GMC engine starts good idles perfect have checked it on scanner 3 times and it says everything is working fine shows no codes catalytic converters have been repaired new fuel pump and filter,EGR valve is good fuel body is good , have had it to the garage 6 times with no change in results above 1500 she coughs through the air chamber and fuel body. would anyone please help me