Thought i was doing some good, had mechanic changing all the thermostat as was broke and now works fine so thats good, fuel filter too got that done, mechanic said fuel coming out was black! And was original fuel filter from 2005! So was much needed! I did the oil and plugs etc... Car was fine for about 20 miles, but now is throwing eml on! Mechanic put snap on code reader on and Saying something like lean fuel, and lamba sensor, air leak somewhere.
he was saying these four codes can all be connected to 1 problem suggesting as my back box is slightly blowing this maybe the cause and the reason the car has been hunting very slightly at idle. Also he said the maf sensor on airbox maybe faulty. But why now!? Is this just a co-incidence after all this work? Or is it related? Car has engine z18xe 2005. Any advice appreciated. Im fed up!