I got a 2nd gen prius about 128k miles so far, and I use a techron fuel system cleaner like a few months ago and when i did it it made the transition between hybrid battery and engine more rough. I was wondering if this was a good thing? It smoothed out after like a couple of weeks and Ive been thinking about doing it again soon. Just wondering if this is good and i should keep doing it and if anyone else also had similar cases like mine as well? Thanks
How much oil does the ICE burn between oil changes? My Gen 2 increased oil consumption just before 100K. Never noticed any roughness though, in transition or otherwise. Were sparkplugs replaced at 100K? You might want to disassemble the intake air piping to get down to the throttle body and check the throttle plate for any buildup around the throttle shaft and edges of the plate. While you're down there, take a look at the inside bottom of the intake manifold for accumulated oil/fuel. It's a difficult clean to mop that stuff out, but can be done if you're careful. Rough transition could be an EGR or PCV problem, or maybe the mass airflow sensor needs a cleaning. There is a special cleaning spray to use that leaves no residue.
This may have been a concentration/mixture issue. Most of these bottles will cover 15+ gallons and you've only got a ~10 gallon tank - dry. I don't think it did any damage, since it "smoothed out", a couple of weeks later and your not putting a lot of mile on it. Lower the concentration; perhaps a half bottle this time - a couple of tanks apart. This is also a symptom of contaminated fuel, which could've just been a coincidence. Good Luck....
