P1336 Crank / Cam Sensor Range / Performance
P0170 Fuel Trim Malfunction (Bank 1)
You should clear the fault codes and see what comes back, just in case the codes are old ones that have not been dleted previously.
It could be the crank shaft or a cam shaft sensor fault or something else. You might be able to use a meter to check the resistance across the sensor pins but I do not know what values to expect. If your code reader does live data have a look at the lambda sensor values - inlet should be switching around 1.0 and the outlet one lower but steady - if not then the one with the wrong value could be faulty and if the outlet one is the same as the inlet then the catalyst may need replacing.
We had a cam sensor fail on a C3
25. Camshaft position sensor failure - 2010 C3, 1.4 VTI petrol.
This happened on our C3, 15k miles. The engine management light came on, anti pollution message, went in to limp mode so the performance was poor. Fault codes were read as P0341, 0342, 0343 camshaft position sensor A bank 1 or single sensor range, low, high. Both the inlet and exhaust sensors were replaced as I thought if one has failed the other may not be too far behind. On checking, the inlet one gave a resistance measurement between all of the 3 pins and the new and exhaust only did on 2 pins. £47 for 2 sensors, they come with new O-ring seals.