Engine Clicking And Tapping Noises problems of the 2008 Chevrolet Uplander

I have noticed right around the time I got this van that just it just started making this clunking sound coming from the rear end and making a noise that I couldn't figure out. The drop down modular has been really bogging down around 50mph and makes me give it more gas to stop the kick back. The engine light came on after buying a set of 4 new tires for the van. I bought what the van recalled and the check engine light came on and wont go off. I have had it checked out and still wont shut off. I have kept the oil changed at required times. I noticed the fuel system also has been giving the van a harsh mpg issues and not sure why. I think it might be the drop down modular that is causing this problem. I now been having since 2011 the clunking sound coming from the rear end axel area and then after reading about the recall today really made me scared to drive this van because I'm disabled and in a wheelchair. I have the lowered floor option and I know its going to need this recall fixed and welded. Please send me a email on how I can get this van fixed. I wanted to also tell you that this van was sold to me at $32,850 and had a blown engine that they didn't tell me till afterwards. At 20,000 miles the van blew up and they sold it to me as new and it was used. They also tried to sell me a extended warranty that was paid for by the manufacture for $3,500. I feel I was done wrong and would not of bought this van if I had known it was blown up at 20,000 miles. I would like to request a review to have it inspected and fixed with the welding that the recall calls for. Thank you.