Ok I have done all type of tests on grounds replaced the Crank position sensor, Cam sensor, cleaned the TB and replaced the MAF and the MAP. Also replaced the coil pack it will begin to surge and then die while driving, it produces a PO 335 code. But now using a tech II scanner each time I try to read the codes I get a screen that tells me if I clear the ECU I will lose data. When I answer yes it does not clear that screen, now the PCM is different from the ecu or is it? Looking for some info on the ECU it is a 2004 chevy malibu with a 3.5 engine 115,000 miles.