Update - the car ran rough for a couple of weeks and Toyota said it was residual diesel. Eventually I ended up with the no start problem again. Toyota took it back and insisted it was residual diesel. The gas station checked their readings on the days I pumped gas and verified there were no issues on their end. The state of CT weights and measures also indicated no one had complained about diesel in their cars. At this point I am sure they misdiagnosed it and charged me $435 to drain my gas tank for nothing. Anyway Toyota kept the car after the 2nd no start and gave it to their top technician. Well supposedly it is fixed now (I haven't picked it up yet) and the culprit was the ignition coil.
Joey - you had written "There is also the possibility of a bad coil, the spark needs to be hot, as in able to gap 1/2 inch of air"
I had written - "I tested for spark the way you suggested using a thick cotter pin. Seemed to jump the 1/2" and the color was orange"
That orange color kept bothering me, I even ohmed out the coil and it seemed good. I've always heard the spark needs to be white/blue. But since I had changed the coil myself about 2 years ago my stubborn brain wouldn't consider this part to go bad, especially because I was replacing the original coil, I figured I'd never have to replace that again.
Any chance when I was down 2 quarts of oil that it made the engine hotter and made the coil fail? Or did I just get a bad coil? ($15 off of ebay) I also read that you should always use a genuine Toyota coil as the after markets weren't as good.
Anyway that's the update so far.
Thanks for all the help.

 

Thanks for the update.

Perhaps should have stated blue spark. One other issue with ign systems and coils is weather, moist or rainy weather can cause starting and running issues on engines having weak ign systems.

Strange how Toyota did the work on tank and not noticed diesel mixed with gas would result in something that did not appear, smell or burn like gas if a match was put to it.

Suppose if coil is built into distributor then low oil could cause an increase in coil temp but not enough to make a difference. Oil does cool engine parts and the less oil, the hotter the parts so keep oil within the hash marks of the dipstick.

Given this the second coil would look into buying a better quality part (not chain store branded product) or shop internet for a discount Toyota parts dealer to get a factory coil.

Suppose if coil is built into the distributor it will run hotter and if not the best quality over time fail faster. Some Toyota Camry have the coil in remote location like the old point and condenser ign system and as such exposed to air flow, the coil is also larger.

Toyota parts are No 1 quality but more expensive. Sometimes the price versus quality can be too high and as such people buy aftermarket parts.