Hey guys, I have a 2009 Pontiac G6 with the 3.5l v6 with about 183k on the odometer.
I have been working and tuning this vehicle for a while. I replaced injectors with OEM injectors, added an exhaust to it that I welded. That's about it on the side of 'mods' and maintenance has been often. It eats about 1qt oil every 1.5k miles. I change the oil pretty often at about 3k mile intervals. Always use Mobil 1 High Mileage Full synthetic. I have cleaned the MAF sensor, cleaned (for the most part) the upper intake.
I got an MPVI3 so that I could get myself into tuning. Figured starting on a cheap vehicle would be best, and so I started learning. Using LTFT I have been able to better work on my idle as it was running 10% rich all across the board. I am still working to get a wideband kit and install that.
As I am tuning the spark, I noticed even with high octane, I end up retarding like all of it as I am getting knock on 91 octane (The highest available at my altitude). Is this because the engine is so old, or because the fueling is off? Does improper fueling affect spark? Here is my current tune high octane table VS the stock tune high octane spark table.
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This is that tune file even had knock on that, right around that higher area and even some that is retarded over 2 degrees.
Screenshot 2024-02-28 200331.png
Over a long trip I had got a random misfire. This happens very rarely. Could this be from knock?
Can provide tune files upon request.