Right so car has the car in, new 02 sensor. Bung in the exhaust. Passed the 02 part of the emissions but failing on the c02.. Now it has flagged a fault code 34 which is exhaust manifold but don't know how old this is. Also no leaks from the manifold that can be seen or when water sprayed are visible.. Maybe map sensor but not sure? Help . Won't pass mot now