sorry swartlkk but I tried looking at your threads its like trying to read a foreign language.

I did a little tune up. I re attached my air filter ( it was completely detached) my mass air flow sensor was broken and my carburetor was filthy dirty cleaned it a little bit and put some fuel injector cleaner. before i did that i was getting about 12 mpgs, then after all that tuning up i was getting 17-20 mpgs then just recently after about a week it went back down to 12 mpgs what the heck is going on?

whoops i forgot to say it's a 98 blazer 4.3 liter 4x4