If the 2000 engine is in a 98, you will have to run whatever was in the previous 98 engine. If the 98 computer is programmed to run with a knock sensor, it won't run properly without it. I put a 2000 3.5 engine in my 98 SLX and ran into the same problem. I had to use the 98 intake and plenum as well. The 2000 was not drilled and tapped for the sensor so I had to do that to install.
2000 Nissan Xterra SE, Daughters toy.
94 Trooper S 3.2 w/ a 5-speed brand new off the showroom floor in 1994.
88 Trooper LS GONE
89 Trooper XS (Red) - GONE to a good home in Alabama
89 Trooper SE (Blackie) - Gone to a good home but won't be forgotten anytime soon!
98 Acura SLX. Sadly, it lost the engine and I can't justify putting any more money in it. Gone to crusher.
95 LS Trooper bought for parts. Now gone to the crusher.
98 Trooper, 3.5 w/ a 5-speed. 15" Snowflakes with 31" AT's, 2" lift with OME 919's, KYB shocks. Manual hubs. My son's DD.
89 Trooper "Blue" 2.6 w/ "Jerry Cam", 5-speed, LSD Rear, Lock Rite in front, Manual Aisins, Big brake upgrade, Rock Sliders, 15" Snowflakes with 31" , AT's. MY DD!