C-Reader codes for 97 F150

I have a 97 Ford F150 4w drive The C-reader OBD 11 is displaying these codes- 0455, 0401, and 0420. Would anyone happen to know what these codes are indicating. Thanks for any help. :feedback:

P0455 is gross EVAP system leak.. Usually bad gas cap or broken hose. The P0401 is Insufficient EGR flow. Usually cured by DPFE sensor or cleaning intake behind the EGR vlave. The P0420 is for Bank 1 converter below efficiency(passenger side if it is V8). Diagnostics of the P0420 is quite legnthly and time consuming to accurately determine if
the converter is bad.

Thank you very much for the information. At least now I have a starting point. I'm sure this is why I have a Popping going on at times. Thanks again. :wave:

What kind of popping are you hearing?? You might want to start another thread since it does not pertain to this problem. We are more than happy to try to help.