With vehicle on ramp I could see there were no exhaust clamps where U-pipes from cats went into silencer box! With vehicle on ground it looked like the pipes were part of the silencer. Put some sealer around and put some clamps on, immediately got lambda figure of around 1.00 at idle and 0.995 at 2500 rpm. Although it did not sound as if it was leaking it was obviously drawing quite bit of air in. Customer did not want me to investigate misfire, he would not even pay £7.00 for some injector cleaner! Shaun.