i have an 09 mcs that had the half power light come on and reduced power. I originally had misfire in 2&4, maf short and retarded timing. I replaced the plugs, cleaned the maf and reset the codes but still reduced power? I order a new vanos switch but still not sure. The engine runs great, no weird sounds or farts, revs to redline easily, getting 33mpg but not getting the turbo power? I checked all hoses etc. I had installed a pos computer chip from performancechips.com that did nothing and wonder if it fried my ecm? I appreciate any help! Any valves etc to check?