Bought a car from this guy for $400 (automatic) but it idles up and down after idling for about 20 seconds and every now and then it will shut off. I've cleaned the iacv, replaced the tps (worked perfect for about 2 weeks then stopped), replaced z6 cam gear with a y7 gear, reset ecu, new map sensor. The only codes its bringing up is for knock sensor and high voltage map circuit.... could the high voltage be it? Bad ecu? Any ideas? Thanks