What is a Code 4?
 

The dealer repaced my pulsation dampener and primary injectors and now the car runs like crap. I took it back in and they cannot figure out what is wrong with it. They said it is throwing a code 4 and they do not know what code 4 is. Anybody, somebody, please help.
Ryan
I asked if they had checked the vaxume lines and pills on the wastegates and they said the mechanic (who is a rotary specialist) went through everything again and cannot figure it out.:(

After calling a bunch of places I am sure theat they are reading the code wrong. I think it is actually a code 40. I have asked them to check it again. Would the purge control valve cause stumbling and backfiring? Anyone know?
Thanks