Please can you help me, basically I put my vauxhall tigra into a garage for and mot, its faild needed a new cat so I agreed with the garage to do the work on my car, they did so put it thru the mot andd it passed I paid for the work done when to collect it and whle driving hme noticed the engine warning light had come on. After the weekend I took the car back and the mechanic sed that the lad who had worked o my car had done this bfore and he had to correct it before for another customers so I assumed that he would fix it and this would be fine. Now they don't know whats wrong with my car are refusing responsibility for the fault of my car and will not fix it. They tryed to fit it with a new sensor but it made no difference and the code the computer comes up with is EGR system. They have informed me they av claned that but the warning light still on what could be the problem? And do you know if this could have been caused due to them fitting the cat wrong?