1. Some difficulty but high quality
It was pretty difficult to slip the header into the collector/mid pipe(this prevents exhaust leaks) and the OE oxygen sensor didn't reach the plug from after market location. W/ 2 ppl and a block of wood/hammer we were able to get it assembled, I cut open the wiring harness to gain a little extra reach for the 02 sensor plug. I'm a seasoned mechanic, overall very happy w/ this exhaust compared to others I have installed/purchased