My radiator was leaking so had a new radiator installed along with new plugs and wires. Same day my van started misbehaving. At times it will not want to start, will crank but not turn over... when it finally does turn over.I have to rev it to give it a little boost to continue running. It sputters and putters. At random times exhaust fumes will be coming out from underneath the back passenger sliding door area.... like a lot of fumes. I did the key flip thing and here are the codes that showed up; P1684-battery disconnect in last 50 starts; P0134-O2 sensor circuit no activity detected; P1297- fuel air metering; P0303- misfire cylinder 3; P0172- bank 1 system too rich. So what in the world is wrong with this thing?? What parts do I need to get it fixed. I am ready to send it off a cliff!!! Please help!