How many miles on the rig? If it’s over 100k, replace the O2 sensors. That won’t do anything for your cold idle situation, but should have a positive effect on mileage (if you go a CEL for the O2s, there’s a reason for that.)
How many miles on the rig? If it’s over 100k, replace the O2 sensors. That won’t do anything for your cold idle situation, but should have a positive effect on mileage (if you go a CEL for the O2s, there’s a reason for that.)