I have P0420 disabled in my car. Is that why I get sh1t for gas mileage recently? I was planning on a catless DP so I just did it when I had the HP tuners(me and some friends rotate). However, modding for the Bonneville has ceased. Will that one code being disabled cause the problem that is in the sticky in the tuning section? Before anyone asks, all the maintenance is up to par. The only thing I that I need to do is do a better job of cleaning out my TB, but I don't know how much that should affect MPG. The car always gets 87 from Costco with 10% ethanol in it. She runs perfectly and smoothly. I just got 16.7 in the city and I didn't cross over 2.5k RPMs in the last 5 days. :/
Thanks for any advice guys.
