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2016 GT350 intermittent surging

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has anyone ever ran into anything like this?

the car was running perfect this last wednesday all day long. then randomly the next morning it was idling weird and i went to take it to work and it was nearly undrivable due to a really bad misfire/surge issue! CEL came on and gave misfire and 02 sensor codes. it was bucking like crazy and afr was like 8.8. rpm was bouncing between 500-1500 on its own. i got it back home barely and towed it to the shop and they couldn’t get it to repeat the symptoms after 4 seperate 45 minute drives. they ran the CEL and nothing came of it. everything looked fine to them so i picked it up and drove it home last night and this morning and it drove perfect. after an hour of driving it today it just started misfiring, bucking, surging and ultimately stalled itself as i got into my driveway. let it sit for 30-45 mins and then started it up and it ran perfect again. this was all after a brand new tank of gas on wednesday night, but nobody can figure out why it’s happening.
I'm experiencing this now. I did the tone ring TSB and that didn't help. I had a crank relearn done but with winter upon me, I haven't gotten to test it since. Mine is a surging at cruise. It is primarily a track car and at WOT it does not seem to happen. I did notice it on the banking at CA Speedway and it almost felt like the brakes were being applied intermittently.
Exp. Type
Exp. Level
10-20 Years
call me crazy but how old is your battery? do you have auto blip or a pedal commander?
Interested to hear how you think those things might play into it. Same problem started a couple weeks ago with my '14. Threw spark plugs and O2 sensors at it but snow, ice and winter upgrades have limited testing. New battery, no auto-blip but I have had a pedal thingy for about 18 mos.
Bay Area
Old battery can make these cars do very odd things. Happened in my Boss and GT350. Auto blip can do the Same. But you don’t have either of those. I’d disconnect the pedal commander and see if it goes away. My autoblip did me wrong, I took it out. Never had issues afterwards.

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