have a civic 04 prosmatec ,it had cng init earlier ,its only 45k done, and i
ve been witnessing very bad fuel average (approx 6.5 km/l).somebody told me that because of CNG the valves get disturbed and they need to be re-done in order to get the actual fuel average. my car has been thoroughly checked by honda and other renowned mechanics (khan ..etc)of karachi and has been found absolutely ok.. things that ive already tried are mentioned below
different airfuel mixture settings tried, now reset to actual as prescribed by honda.
gear ratios reset.
Also tried different driving patterns...no help!
Would really appreciate some advice or if somebody in khi who is an expert of heads/valves can be referred to.