No gas leak, replaced fuel filter,MAF,tps,air filter,plugs/wires,iac,throttlebody,and other parts in the summer, was getting ok gas milage about 12-15 mpg city. while at a junk yard I seen the same truck/engine 2.3 with a new fuel rail and better looking fuel injectors and fuel regulator. I noticed after I got mine apart that the injectors were a little smaller, so I just put them in.. noticing that the plastic tip on one of mine was broke. I replaced all but one, it kept leaking after 3 new o ring seals , so I put one of my old ones in, and it runs fine, but now I'm getting about 7 mpg!! is it the smaller injectors? also I have a locking gas cap, so no one is stealing gas, also have a new o2 sensor. note there is no egr on this engine this year, came like that from factory. again idles and runs fine. maybe a bit rich smell, but what would cause my gas milage to be cut in half.