[MMGT1]

Lets look at one of GMs more recent screw up shal we...lol
The 3.6L VVT in the CTS 2004-2007 especially, both the regular 220hp version and the HO 255hp version. Factory programmed for 7500kms oil changes. This was more than the chains could handle. I saw at least 3 a week for two years having chains replaced. They would stretch and throw cam timing off setting a DTC for phasing. Once chains were replaced the PCM was reprogrammed to set oil lamp at 5000kms... Just saying, don't trust that dam manual for everything!