2015 Roush Stage 3 with Tune runs poorly intermittently

[leroc]

Has anyone ran into this issue. Car will run perfect for several days. Then without warning, car will run very rich, knock, stumble, exhaust smells bad, rough idle, then back to normal. Replaced valve on back of supercharger. Replaced spark plugs. Checked injectors. Swapped MAF Sensor. No codes. No freeze frames. Any ideas are appreciated!

Car running well: First File
Car running poorly: Second file.
Car running poorly in Sport Mode: Third file.

[Sweet35th]

When its acting up, fuel trims are crap. Pulling lots of fuel. Then goes lean, and over compensates trying to add it back in. . Given its a rich condition at low load, but not at mild + load, I would suspect that your canister purge valve is stuck open. Especially given the fuel level of the |"1 mile drive" log. Engine at light load high vacuum is likely drawing in uncommanded fuel vapor screwing with the fuel trims. Then when you get to higher load, and the vapor is not sufficient enough to cause the rich condition anymore, the LTFTs are pulling fuel out still, and the STFTs move up to try and correct for that, but not quick enough and you get knock.. With engine running, unplug the purge valve, remove the line from the valve that goes to the fuel tank. With the engine running and valve unplugged you SHOULD NOT have vacuum on the side going to the fuel tank.

[leroc]

When its acting up, fuel trims are crap. Pulling lots of fuel. Then goes lean, and over compensates trying to add it back in. . Given its a rich condition at low load, but not at mild + load, I would suspect that your canister purge valve is stuck open. Especially given the fuel level of the |"1 mile drive" log. Engine at light load high vacuum is likely drawing in uncommanded fuel vapor screwing with the fuel trims. Then when you get to higher load, and the vapor is not sufficient enough to cause the rich condition anymore, the LTFTs are pulling fuel out still, and the STFTs move up to try and correct for that, but not quick enough and you get knock.. With engine running, unplug the purge valve, remove the line from the valve that goes to the fuel tank. With the engine running and valve unplugged you SHOULD NOT have vacuum on the side going to the fuel tank.

Thanks for your response. Purge valve on the back of the supercharger was inspected (no issue) but was replaced anyway. Issue still persists.

[chevota]

I'd imagine it's of no use on your car, but it's all I got:
Mine did similar when tinkering with my Minimum Spark table, which I was bumping the minimum #'s so it wouldn't go negative all the time. It screwed up my fuel, bad, but only under higher loads. Putting around was usually fine.
Another, which screwed up fuel altogether, was adjusting the load scaling on the fuel map to reflect the newer/higher loads. Oem went from 0-170% Load, and I simply changed the 170 to 200. It ran so bad that it would barely idle.
The moral of the story is I've learned that you never know what a change will do, at least on my car.