I was commissioned to groove the above vehicle for a customer this past weekend..
The results of the modification are total reduction of fuel smell in the exhaust, no "noticeable" increase in power, and a loss of 1-2 mpg's. The customer says that he generally gets 17.5mpg city and 18.5mpg highway and this first tank has him at about 16.5mpg partial city and partial highway.
The purpose for this post it to show you the work that I did via pictures and then to discuss the things that I can do to at least bring his MPG's back up to base line and potentially improve on then a mile or two per gallon.
I talked with Tracy G. this evening and he said that I need to focus on the O2 sensors and possibly the ignition system as well. After thinking about it for a while, I believe the customer told me that the spark plugs had recently been changed however I still need to ask him about the O2 sensors.
Thank You Again Tracy for spending some time on the telephone with me!
I also know that getting me something to plug into the OBD2 port for real time information would be helpful in learning and diagnosing some faulty sensors.
Please get with me if you know of anything I can do to rectify the situation and keep a happy customer.
Below is a picture showing the area that needs filled to the left and right of center to prevent the groove from cutting through the outside of the throttle body. Also notice the small triangles on both sides of the middle section that also need to be slightly filled. The center is where the idle air bypass is on the inside of the TB. Rather than make a gasket, I opted for filling the idle air bypass with JB Kwik (as it needs to be slightly filled to prevent cutting through) and then drilling out a 3/16" hole for the idle air flow. I was able to achieve idle by slightly adjusting the idle set screw in about 1/4 of a turn.