Every spring I get a wild hair. Last year it was new speakers. Year before, it was my noise abatement project. This year it's messing with engine controls.
I ordered a scanner attachment for my laptop, an ElmScan5 from ScanTool.net, through Amazon. I loaded the software on the PC according to the directions (of course!

) and attached the interface to the computer and the car. WOW!

NEAT!! The default dashboard shows a speedometer, tachometer, fuel flow, trip distance, instant and cumulative fuel consumption, engine temperature, and engine load. It's possible to make a custom dashboard to show other stuff, too. Trouble codes can be read and reset. All for $44.31 US. Enhancements available for a nominal extra charge.
I also got a Volo Performance VP-12 to improve the performance of the 2.7 engine and, hopefully, go a little farther on a tank of gas. I installed a couple of mating Molex connectors from Radio Shack to plug it in when I'm ready after I watch the numbers from the scanner for a few days. Not that I'm doing a detailed before/after experiment with the VP-12, but I want to get an idea what the ECU is doing as I drive normally.
So that's this year's idea. Results forthcoming.