I was hoping somewhere could help me. I just bought an 03 trailblazer ls. When I got it it said it was misfiring in cylinder 3. I replaced all the plugs and the coil for cylinder 3 but it's still misses. Anyone have any other suggestions?

 

when posting include the year and engine
assuming the miss remained on cylinder three?
with a scan tool check the misfire monitors for all cylinders...is #3 the only cylinder accumulating missfires. Is it misfiring only at idle, at 2500 rpm or all the time?
if only on #3 and all the time....do a compression test