Take your car to the dealer. Your ECU needs to be reflashed. There was a big problem on that and it basicly dealt with bugs in the fuel maps. Also, what type of air filter are you running? Mazda's with the MAF (mine has a VAF) meter don't run very well if you're running a K&N filter and you're using the oil based charger. It coats the MAF and runs basicly how you're describing. If he (your mechanic) has the equipment, have him check fuel trim and/or datalog it to make sure that you don't have a boost leak too.