Your mechanic may know your vehicle's engine condition overall, and perhaps there is quite a bit of work to do in order to get it to pass the smog check, but then again, their might not be. We'd recommend investing $150.00 (or so dollars, usually diagnostic labor rates start at $85.00 hr and take approx. 2 hours) and have a smog check certified mechanic diagnose your van's smog check failure for an accurate explanation of the possible faults. You may then make an informed decision on whether you should junk the van or not. If you do choose the retire it through the California Buy Back program, you may receive up to $1500.00 for it. Check out... How can I retire my Dodge van to the State of California?