i went to get the bronco smogged and i had all sorts of issues. i found someone sometime installed a DuraSpark III ignition system. this is for a feedback carburetor.and CA trucks. this is a FED 48 truck. see the wireing mess.

the DuraSpark III uses an O2 sensor. so the smog rep said this has to go.

Here is the O2 high alt sensor and the DuraSpark III unit (not no blue color band connector.

Here is another view of the DuraSpark III box

this is the under the dash EEC. gone now

the connector on far right is the altitude sensor. the plug in the middle is the O2 plug. it all comes out and tossed in the trash.

and here is the blue connector DuraSpark II module. if you are converting from a feedback carb system you will need a non-feedback carburetor, a DuraSpark II distributor and the blue DuraSpark ignition box. check local smaog laws.........this drives so much better now.