My car has been having intermittent issues. Sometimes it will start but only for half a second then die. I can give it throttle to keep it running but if i let go of the throttle it dies. If i hold the rpm at 2000 for 30 seconds or so it smooths out a little but idles very sluggish. I recently went through all the vacuum lines and there are no leaks. There is no unmetered air after maf sensor. I pulled codes and i got 32,33,34, and 45. Reset codes after cleaning up vacuum lines and havent had the issue since. I noticed i have a granatelli aftermarket maf sensor on the car. Does anyone have any experiences with these maf sensors? Are they just snake oil? I do have a few mods on my car and apparently that helps the computer get a/f ratio when you increase air flow with say a cam and headers.