Ive got a 98 GT 4.6, auto. 146,000 miles, new plugs, wires, coils, K&N air filer, fuel filter, and harmonic balancer.

It had 3 codes when I got it home, first two were bank 1 & 2 lean. Other was an emissions code, cleared and havent come back on in 30 miles. I got the codes wrote down in the car.

Now its got an idle issue, when its cold it idles high. About 2000 RPM and sometimes it will idle like its got a bad IAC. Up and down slowy, from about 500 to 1600 RPM then smooth out at 2000 for while and finally drop down to like 700. Runs good otherwise with only a slight timing chain rattle at high RPM in second gear. IAC is good, any ideas?

Another issue, it vibrates bad. Kinda feel it at idle but more so when acclerating. Almost feels like something in the trans, it was replaced with a reman unit a year ago. Feels like its slipping slightly at WOT shifts also. I thought the balancer was the issue so it was replaced but no change. It was coming apart/cutting into the timing cover so it WAS bad. Motor mounts seem fine, engine doesnt move around more than normal. The vibration is also there if you just rev it in park, so its not a drive shaft/rear end issuse. Bad torque converter or cracked flywheel maybe?