It is the air temp sensor - I strongly suggest NOT unplugging (you will get a code) or relocating it - it is an important part of the monitoring system. Get a better flowing muffler like the PowerVault, change ALL your fluids to synthetics, run maximum air in your tires (see tire sidewall) and avoid jack rabbit starts - but there is NO magic cure for a slightly underpowered 4K lb 4WD vehicle.