I'm sorry just curious, why does your megasquirt tune better than a tweecer? when in a tweecer you find everything that was built in your factory ecu and it can all be changed.......plus a megasquirt is more expensive than a tweecer. hell even having a chip burned will be more expensive than a tweecer....but getting back to the topic you will need to have a some kind of tuning device or someone to tune it for you.... now personally i don't like to have any idiot messing with the health of my engine that is just my opinion. I got my tweecer for 520 shipped and ready to install..... but then again i already had a wideband O2 installed in the car. but basically my car ran like crap and with the 24lb injectors and pro-m mass air. i wsa fouling plugs left and right. so i decided to tune the car with a tweecer and it is the best investment you could think of.totally worth the. i desabled my egr and thermactor system, set my injector slopes and breaking point advanced timing electronically by 4 degrees and dialed in my mass air flow sensor and the car now runs a on a steady 12.5 Air Fuel Ratio at Wide Open Throttle and it cruises at 14.7 Air Fuel Ratio, so mileage has significantly increased and it runs like champ.... totally worth the money Just my 0.02 Cents..