Jason, looking at an earlier posting of yours, you say this engine has an 02 sensor I think it is safe to assume that this truck has a service manager/ecu, and therefor codes should be displayed on the dash display if this truck is a vex model. If you look in the mechanical posting picking out your particular truck model some one may have described how you access codes with regards to your truck model.
Regards Titus
Jason, is it possible to to give more details about the truck,
Model and serial number would be helpful.
Regards Titus