Smoke test and/or boost leak test. If neither of these work test your idle air control. The car runs fine when you push the throttle a little and just wont idle? Or stumbles through the whole RPM range and dies when you let off throttle? If it stumbles/misses at any RPM above idle, then it isnt an idle control issue. Ohm out your injectors as well if you suspect any issues there since they go out commonly. Check MAF as well. Try unplugging and see if it idles.