Afr problems
 

I have a 87 rx7 turbo with 45k on the rebuild. it has a medium street port, fmic, 3" turbo back exhaust, full emissions delete, the throttle body mods, 550cc primaries, 680cc secondary's, s5 turbo swap with a turbonetics to4b h-trim compressor. im currently running about 12psi boost.

ok i have an aem wideband afr guage, and lately my afr's have been going nuts. It used to run around 12 at idle, 14-14.5 at normal cruising and would be around 10-10.5 when its in boost. it would never get above 15. But lately its been jumping between 12.5-14 at idle and between 14.5-17 at normal cruising. its still staying good in boost though. I have checked all my vaccum lines and block off plates for leaks, found none. and checked all my intercooler piping and found no leaks. i cleaned my afm out and tightened my bov in case that was leaking. i cant figure it out and dont wanna do any damage. any help would be greatly appreciated.