My dad just bought a 1996 F-250 and the check engine light was on. It was giving him codes 141, 171, & 174. We checked the fuses inside the truck and all were good. We checked fuses under the hood and found a blown 20A fuse on near the fender on the left hand side. My 95 service manual indicates it is the Radio fuse. My dad's 96 manual doesn't give him a description. Once we replaced it, the 174 code cleared. I know 171 is the code for running too lean as well as 174. I thought it could be the downstream oxygen sensor but wasn't sure. Right now, the temperature gauge isn't working and won't peg out when grounded out. We replaced the temperature sensor but that disn't help. Is there anything else we can try? Also, what could be causing the 141 and 171 to stay on?

Thanks,

Chris