This guy sells a $40 O2 Clamp + a $20 pressure switch(or maybe Stillens' Hobbs Switch?), so you can avoid lean tip-in which is when you boost during partial throttle, closed-loop, and the ECU tries to fight the richer ratios then stoich before it enters open-loop. If you've ever experienced pinging/detonation under light throttle, this is probably why...

It would be great if somebody with a WB02 *COUGH**StephenMax**COUGH* would log this "lean tip-in" and implement this guys solution....http://forums.maxima.org/showthread....=1#post3969929

 

i actually bought a pressure switch a couple weeks ago to do just this, since i was running lean at partial boost below 4k rpm due to closed loop. except, instead of clamping the O2 voltage, i was going to either cut O2 voltage or activate an O2 simulator upon boost. I just haven't gotten around to wiring it up. nice to see that i'm not the only one with this problem.

as far as logging WBO2 goes, it's pretty straight forward. my FJO always reads around 14.7 when i'm in partial throttle, partial boost, below 4k rpm. Above 4k rpm, i'm around 11.0 to 1 AFR.

 

a pressure switch with an O2 sim would be a very basic and effiective way of solving the problem

just rig up a relay the presure switch trips when in boost to switch the O2 wire or for 4th gens 2 wires

 

the setup could look somthing like this



also heres a page that shows how to biuld a basic O2 simulator for about $20

http://www.mkiv.com/techarticles/oxy...sor_simulator/