According to your fault code the definition is something else so can you please post the fault code again..................Can you tell us is the fault code b116804 or, 16804 if its 16804 than here below is the result for your code

16804/P0420/001056 - Catalyst System; Bank 1: Efficiency Below Threshold

Also which malfunction lights are ON on dash.............? See the link below for more info regarding your fault code...........

http://wiki.ross-tech.com/wiki/index.php/16804/P0420/001056

Hi, can you please upload a data log for our engineers to check this problem? Thanks!