That sensor is just to tell the computer the incoming air temp. Since you are now drawing air from all around the engine compartment then it is okay to just tie it up out of the way somewhere and it will still read the ambient air temp in the area. I have mine tied to one of the brake lines.
Now you got an early 99 so all you should need is a 3" PVC 45 and an air filter to do the standard DIY open air intake. Here is a part number cross over list for the filter. Surely you can call around and find a better price on one of them. I buy my Baldwin brand (
Baldwin Filters ) for $38 and it lasts about 2 years. So for around $40 and 10 minutes you can do the normal DIY intake. Cheap insurance for a $10,000 engine.
PA2818 NAPA GOLD 6637
PA2818 SCHUPP SL12903
PA2818 WIX 46637
PA2818 WIX 546637
PA2818 WOODGATE WGA1138
PA2818 ACDELCO A1474C
PA2818 AIR REFINER ARM08-5011
PA2818 BALDWIN FILTERS PA2818
PA2818 BIG A 94637
PA2818 CATERPILLAR 3I0003
PA2818 CARQUEST 88637
PA2818 CUMMINS 2912986
PA2818 CUMMINS 3912020
PA2818 DONALDSON B085011 H
PA2818 DONALDSON ECBO85011 H
PA2818 DONALDSON ECB085011 H
PA2818 FLEETGUARD AH1141
PA2818 FLEETRITE AHR81141
PA2818 FRAM CA6818
PA2818 GFF AF359214
PA2818 GENERAL MOTORS CORP. 25177209
PA2818 HASTINGS PREMIUM FILTERS AF2329
PA2818 HERCULES B085008
PA2818 KRALINATOR LA1458
PA2818 LUBER-FINER LAF2533