About a month ago I pulled the intake and installed the alminium cover. I put everything back together and the engine fired right up. Prior to the repair I was getting about 13.3 mpgcorrected for oversize tires.My weekly trip to work involves driving 280miles round trip. My first trip after the repair I got about 11.9mpg. I chalked this up to pushing very heavy winds. My next two trips the mpg returned to 13.3 mpg. I figured the plenum leak must not have been very bad and resigned myself to 13.3 mpg.

This week my mileage has jumped to 15mpg. I have not changed my driving habits. I use the cruise set for 67mph (corrected for oversize tires it is 70mph). I do not have any stop and go, it is 140 miles there and 140 miles back. Normally the fuel needle is right on the last hash mark, the fuel light comes on about 5 miles from home and it takes me 21gal to fill the tank. Last night the fuel light never came on, the needle is on 1/4 tank and it only took 18.7gal to fill the tank.

Is this the computer adjusting itself to the repair or me just getting lucky this week? I disconnected the battery when I did the repair and figured this would reset the computer, is my assumption incorrect?

 

That's how I get rid of my check engine light after I take care of the issue causing it.

 

Yes it takes the PCM a couple hundred miles to adjust, so the plenum obviuosly helped your mpg