996 tt P0491 & P0492 codes plus ABS/PSM plus 0.5 bar?

[rgracin]

Hi. I have an 03 996 Turbo that is only boosting to 0.5 bar. The ABS kicks in every now and again for no reason and the ABS/PSM lights show very occasionally.

I have read the codes with a fairly basic reader and it showed up the two in the title. No wheel speed sensor codes. Now, could the faults be related? I know MAF's can throw some strange symptoms, (I own Mercedes!!) so I'm after some advice of where to start looking.

Thanks

[thegoose]

Failed MAF will throw up PSM & ABS lights. Unplug the MAF (the car will revert to a standard base setting), if that improves it then fit a new MAF.

[rgracin]

Will try that, but the lights coming on happens rarely. Idle can be a little lumpy when cold.

Could MAF throw the secondary air injection codes?