Local mechanic has had my car opened for about 4 hours now. I had an EGR flow malfunction code. The last time I had this issue (2 years ago) it was because of a clogged manifold I believe. Either way I trust the guy 110% and hes doing work on this car. Tests everything every passage is clear, still throws the code. Hes worried it might be a computer issue at this point. I was supposed to inspect Wednesday. What should be the next step?