JamminJamen

I have a 1996 Ford f150, 5.0, 5 speed. I am getting the 4 codes listed in the title and I cannot seem to figure out what is going on. In addition to those codes a p0300 random misfire code is coming up after driving for around 100 miles, and it idles rough. I have replaced all but the downstream o2 sensor with Motocraft replacements. Still getting the codes. I have replaced the plugs, wires, cap/rotor, used brake cleaner to check for a vacuum leak on the intake manifold, checked all hoses/connections, checked fuses/relays, replaced the pcm, and I have tested voltage to the o2 sensors. The voltage is; 12v to bank 2, fluctuating between 5v and 8v on bank 1, and 4v on the downstream. There is also a small exhaust leak on the driver side manifold. Could it be the downstream malfunctioning and setting off the other codes? Is the voltage within specification? Am I missing something?

Any help would be great. I am one more burnt knuckle away from taking it to a shop.

stromius

Ever figure out what caused these codes? Same year, same boat.