Coolant was leaking into unknown area of engine, no white exhaust, no milky oil. Replaced about 2 quarts of water every 4 days or so. Last week I removed and replaced manifolds both Lower and Upper (plenum) gaskets. Installed new thermostat, refilled with new Dex-coolant, bled system. Engine ran fine for several days. No coolant leaks. Then yesterday the Engine light came on and codes P2138 and P1125 appeared on code scanner. Seems to direct to Throttle Position sensor. I am concerned that wires (harness) to TPS might have become frayed while wrestling to remove and replace both manifolds. At any rate, car just died at intersection. Turning key results in no activity from starter. Battery is good, lights, horn etc. But no activity from starter. Any thoughts are appreciated.