2003 Ford F150 4x4 king cab pickup 4.6 engine 185000 miles, Automatic trans, pickup runs but has low power. Replaced plugs, all 8 coils, all 8 injectors, cam position sensor.
Compression test.
Left side 125 psi
Right side 100 - 75 psi

Codes
Left bank Lean
Right Bank Rich

Any ideas from here?

 

Moved this to the appropriate forum to get more input.

 

Welcome to FTE!

Hate to say it, but it sounds like you have an internal problem to deal with. 125 PSI is decent for your left side, but the right side compression numbers aren't good. The fact that all of them are low suggests that you may have a timing problem. Has the engine made any abnormal noises, particularly on startup? A wrecked chain tensioner could cause the timing chain driving your right side camshaft to have slipped a tooth and fallen out of time.

If no abnormal noises, I'd try squirting some oil down each of your plug holes and running your compression test again. If the compression comes up on your right side, it's bad news. The oil can temporarily seal badly leaking piston rings and cause the compression to temporarily rise. So if the numbers rise, you'll need a new engine. I don't know that it's the most likely cause, but certainly the easiest one to check from here, so it's where I would start.

 

Thank you for the help.