I just purchased an 09 Wrx 265 and was looking to upgrade it a little. I have an Accessport on order from Perrin which will include a custom Perrin map. There is a down pipe and exhaust mod to the car already (Not sure exactly what it is). And i plan on getting a cold air intake (maybe Perrin). I know that certain mods may cause the car to run lean due to the MAF sensor, So if i have a custom tuned map will it ensure that the car doesn't run lean?
No OTS (off the shelf) map will ensure anything right off the penishead.
Now a protune will do you nicely. I notice you were looking for a CAI for it, but the stage 2 COBB maps don't support a CAI.. Only a SRI. Get a COBB SRI or the AEM intake they have the maps tuned for. Don't stray from the maps at all if you want a reliable tune.
2002 WRX Sold
2007 WRX Sold
2007 STi totaled
2007 Foz XT sold