03 X no start

[jharvey55]

Big problem. Wanted to do a full tuneup on my X 3.3 non super. I replaced the t-belt, water pump thermostat plugs wires cap and rotor. When put together I had a knock sensor code and 2 throttle position sensor codes. The vehicle stumbled and cut out at times. I have tried to test the knock sensor but why would it just go out. Now the big problem. No spark. I have tested and replaced the distributor, taken off the timing cover to check the timing. I can no longer get a data stream on the engine with the scanner. Could the ecm be toast?