i wonder if the mechanic put the wrong plugs in? didnt the non pi and pi head take different plugs? but any whoo, the plugs are good and i gaped them. it was one of the first things i did before spending any money. I also went by an auto parts store today and had a dianogstics ran and it cam back as 5 different code wich are p1504 p1443 p0401 p1401 and p1409. one is an idle control, the other is the egr, and the three other has somthing to do with emissions but not sure what it is.