So I came into a really clean 98 GS with 155K from a relative about 3 weeks ago. The SES light was on when I first drove it but a mechanic had ensured my relative there were no major issues aside from a slow leak in the power steering pump. I drove it about 150 miles home with no issues whatsoever. About a week later I started getting really inconsistent boost at anything past 1/2 throttle, and a nasty chirping, stuttering noise. I visually inspected all the belts and they all look fairly new and working. A few days after that, there was a new code for a cylinder 3 misfire. At 1/2 throttle, it accelerates completely smooth until it gets to about 40-45 mph, when it misfires and hiccups, then eventually smooths out. There's a very faint knocking that I can hear if I'm standing directly in front of the engine bay and a very slight misfire at idle. I'm running some injector cleaner through it right now, hoping that will help some. Just wondering if any of you had experienced something similar.