This is a great example of why you would want to have a local dyno tuner tune your car. Mail order tunes are based on the tuners interpretation of how your car is set up. Take it to someone local with a dyno and have them tune it for you. Without a wide band O2 sensor, you have no idea what the car is doing and neither would a tuner that has no idea what your car is doing because they are not there with the car using a wide band on it. Based on the readings from the wideband, the local tuner can make the proper adjustments for your mods. If you go mail order, it's just a guess tune.