I had a guy change out four of my injectors that I couldn't get to and now my "91 deville is running worse than before. I was getting great gas mileage and everything before changing these last four. I couldn't get to them and was afraid of messing with the alternator and power steering pump. Could these injectors be clogged? Anyway to clean them out or whatever. I may have to order another set from ebay. They were pretty cheap.