My 97 Ford F150 with a 4.6 litre will not idle in gear properly it idles just fine in park . I replaced both Ignition coils because they were the original Ford factory part ,Truck has almost 172,000 on it ..Just wonder if oxygen sensors would cause my problem. Plugs and wires seem to be ok . I was troubleshooting out of Haynes manual . Any thoughts out there . The truck also has a new Maf sensor .