At idle they,re around +/- 2 or 3. When driving they may go +/- higher. If you start getting +/- 20 to 30 plus, this means the ECU is having to do a lot of " adapting " to get the injector to " squirt " at the right time.
I,ve found that the " roughness " figures for the injectores are,nt the, " bee all ", and, " end end all ", and if the ECU cant " manage " an injector, it will log a fault code.
Del.