The Engine Control Module (ECM) on a 1998 Jeep Wrangler Sport 4.0L is located
under the hood, typically near the driver's side firewall. It's often mounted on the inner fender well or on a bracket attached to the firewall itself. It's a relatively small, black rectangular box with various connectors.
However, the exact location might vary slightly depending on specific options or modifications to the vehicle. It's best to consult a repair manual specific to your 1998 Jeep Wrangler Sport 4.0L for the precise location with a diagram. You can often find these online or at auto parts stores.
