Freetomakemistakes

Hi, we recently bought a 2004 WJ Special Edition and it ran fine, but with intermittent reverse lights until one morning, while warming it up it just stopped.
We thought it wasn't getting fuel because it cranked but wouldn't turn over. Replaced the fuel filter and spark plugs ourselves, still wouldn't sart.

Found this forum and how to get codes from the car. Received codes for a bad crank position sensor. We had a mechanic replace this and he mentioned there was a neutral safety switch connection issue. Asked if we had pulled on any wires, we had not.

She ran GREAT for two days, reverse lights working again, a little ticking in the motor when cold, but no other issues. Now, there is power, but no engine engage. Turn the key, get nothing. I checked for codes again and it gave me P1489 and P1490, looked it up and it is another sensor.

I want to be sure we aren't throwing good money after bad to get this working - can anyone tell me if fixing the related sensor is the course of action, or should we get a new control chip instead?

Sorry to be so long winded, wanted the whole story out - I searched for an answer, but became confused with all the options.
Thanks