1992 Nissan Maxima car constantly smokes, more on reving/dr

Engine Performance problem
1992 Nissan Maxima 6 cyl Front Wheel Drive Automatic 172k miles

I was getting a puff of black smoke, rough start, and carbon buildup on my muffler. I had injectors cleaned and reinstalled 2 years ago. I decided to check the front 3 since they are the easiest to access. I pulled out the 3 injectors, bottom o-rings on 2 were bad. I re-installed injectors with new o-rings and lubed o-rings with petroleum jelly. Now when I start it up, it seems to start up fine, run fine, idle fine. But now im getting white smoke constantly. From what I here white smoke when running = blown head gasket cracked head. But it did not have white smoke before I decided to change o-rings, and I did nothing else to the car. I let car run and idle for about 15 minutes and I still get the smoking problem.

What is causing the car to constantly have white smoke? It's impossible for me to have cracked the head or blown the gasket while my car was off and I pulled 3 injectors with easy access.