Hey Ive got a 97 f150 scab with 176k on it. saturday i replaced the battery terminals and ever since than when i come to a stop in drive the truck shudders and the rpms drop way low usually below 500. any suggestions on whats casuing this?

 

Mine did the same thing and it was an electrical misfire, so I took turns unplugging the wires from the coils and seeing which cylinder made the least difference at idle and I checked them because that means that it already has a slight miss.

Then I found out that when I replaced my thermostat that water/ antifreeze mixture got around the front driver side plug and caused it to have a weak spark.

It wouldn't hurt to check the plugs as well

 

Wouldnt it have done it always though not just after i did the terminals?

 

Any change in electircal current can start expose any electrical firing problem