If the injectors were performing so poorly that the engine fell flat at 5200 rpm, then they are still performing poorly. The techron might have unplugged them a bit but you can be sure that they still drip, have poor spray patterns, and are out of calibration.
The fix in a bottle might help the situation but it doesn't fix the problem. I'd really recommend pulling the injectors and having them cleaned and calibrated. You'll be truly shocked at how much better an engine runs after having this done.
And if you haven't replaced the fuel filter in awhile, I'd do that too. You'd be amazed at how dirty even good gas is these days:
Don't Forget to Replace the Fuel Filter
Here is the report on my fuel injectors that I recently had cleaned/calibrated. The engine ran fine but seemed just a little low on power.
