has anyone ever tried them i was doing a few minor tune up on things and noticed my coils had at of rust on the connection and wanted to replace them but was curious about these on zzp site for 119.99 for the set of 3 or 3 stock coils for 60...also my o2 extension got fried on my headers so replaced that but my o2 i think it going bad either from the connection getting fried or just time to replace... anyway to know signs of bad o2 like loss or hp or surging or anything like that