Google says that NAM says P1498 is (Unmetered air after compressor) Check for leaks in the intercooler or the tube that goes from the back of the SC to the TB.
Just to add another possibility for anyone looking for information on this code down the line, I've been getting this code recurring for a week or two with no apparent change in performance. I could not find any apparent leaks in the IC boot or other tubing. When I did an oil change a couple days ago I checked my oil catch can and discovered that the can itself had broken. I did a jerry-rigged patch on the can by wrapping it completely with high temperature electrical tape which seems to have eliminated the EML light/CEL code.
This does, however, open the possibility that leakage in an OCC or the connecting tubing can cause P1498 code. In my case, The code did not always appear when the EML light went on.
I found it. I have an oil catch can. I have a plastic 90 degree tube going from the hose off the PVC valve to a hose into the catch can. The plastic tube had a stress crack.
I experienced this same fault code when I installed my boost gauge. The hose coming from the fuel price regulator to the t-connection for the boost gauge has popped off. I too had trouble finding the fault code.
