Originally posted by evotunedscc
To keep this simple, check fuel pressure at idle and boost. Get a voltage clamp and ditch the SAFC. Anything else?

No thats about it.

It could be something as simple as your Fuel pressure is't raising enough for the boost you are trying to run. I know I was trying to run 7 psi and I was only getting 75ish psi of FP at the rail when I needed around 100 for stock injectors :P Once I got the sfmu tuned properly it pulled like a muther compared to running soooo lean under boost :)

And seriousley, that narrowband means nothing AT ALL to me. I'd sell the SAFC and find a Zeitronix wideband to actually SEE what you a/f ratio is.