EGT probe is for sure nice to have. If you have the EGR deleted already you can very easily drill and tap the rear block off plate. If you don't have the EGR deleted then you'll have to drill and tap the exhaust manifold. It's nice to have just to see how hot your truck is running, also you can use it to control your right foot for fuel mileage if you want - lower EGTs = less wasted energy but your boost pressure on the Insight can help you with that as well. Even towing you can run your EGTs high so it is nice to monitor :thumbsup: