Ford Escort - 97 1.8 failed MoT on emissions - high Lambda readi - carmalade
The CO and HC readings are well within spec.A high lambda reading on this car seems to indicate a leak in the exhaust system (sucking in air).Check the joints and seams for any cracks or pinholes from the lambda sensor area to the rear silencer box.An unsteady idle could be caused by a faulty pcv valve .It is situated behind exhaust manifold,by #4 cylinder .Also check the rubber elbow attached to it.hth