I was using a Brenspeed 93 octane tune (great tune) for about two years straight. I moved to a city with heavy traffic my mpg went down to 15 and I decided to switch to 87 octane to save money since I was just sitting in traffic most of the time anyways. I used the "stock" SCT XCal 3 87 octane Fuel Economy tune. After driving less than 30 miles the check engine light came on. My vehicle is 2008 GT with about 76, 000 miles (the vehicle is very well mechanically maintained).
I’m going to go home tonight and teach myself how to use the XCal to read the code, but has anyone had similar experiences? Is it “bad” to switch from higher to lower octane gas even when you use a tuner? I understand there is the chance that it is a coincidence that I changed the gas and the light came on but I figure with all the regular maintenance I do (myself most of the time) that this is unlikely.
Thanks all for your help and thoughts.
I’m going to go home tonight and teach myself how to use the XCal to read the code, but has anyone had similar experiences? Is it “bad” to switch from higher to lower octane gas even when you use a tuner? I understand there is the chance that it is a coincidence that I changed the gas and the light came on but I figure with all the regular maintenance I do (myself most of the time) that this is unlikely.
Thanks all for your help and thoughts.