.... a little late to the party but......

If you are using the low impedance siemmens injectors get yourself a pair of 1 ohm resistors. The injectors are wired in pairs and you ideally want one resistor per pair.

The stock 951 injectors are an odd ohm 4-5 ohms.... so you use a 1 ohm per pair to get those low ohm injectors close.

In regards to your last question.... If its like any other wideband guage you can blip the throttle and the AFR will jump ......... what display are you using?

I actually have 2 widebands....don't ask. It was all in the name of science. ONe in the stock location and one on the dump pipe. One reads leaner. I will leave that for all the gurus to determine. :D One spot is approximately 0.5 leaner.

P.S Shameless plug - if anyone is looking for three 55lb siemens low ohm injectors with less than 2000 miles on them. CHEAP. I went with a high ohm setup for MS.

don't you mean resistors are required if one is using high ohm injectors? otherwise, how would resistors increase ohm if they resist? it makes more sense they'd resist, and decrease ohms.

also, which sensor reads lower? and are they identical make/model sensors of the same age? i'd think as sensors get old/worn, they'd read leaner.

Resistors add resistance if connected in series (i.e one after the other). They decrease resistance if connected in parallel (i.e next to each other)
Total R = R1+R2....Rn (resistance in series) where R1 and R2 etc. are individual resistances.
Total R = 1/(1/R1+1/R2+1/Rn) (resistance in parallel )
The sensor down stream may read lower if there is any combustion in the dump pipe, or richer if any dilution occurring down stream.
Sox

I get 2 number reading from my gauge. One pops up when the car is firing up/idling (the number is usually around 60) once I turn it off the number starts counting down. The other number is 17.XX (I'm guessing my A/F ratio) But it doesn't seem to let me toggle between the two and keep one up on the display. Also, the "rainbow LED" is always pegged to the right (red).