Duke6893

About a week ago on a very hot day, my car had trouble starting. against my better judgement I drove it to work and stopped along the way and it wouldn't restart. The ses light was on. I let it sit with the hood open for 10min and it finally started and I drove it to work. lunch break I went out and it fired right up. after work It fired up and I drove towards home. It ran fine for 15min and then quit at a stoplight and wouldn't restart. I pushed it to the side of the road and called AAA. an hour later a rollback showed up and it fired up and ran for a min for me to line it up with the truck and quit. got it home and it ran long enough to get it in the garage. Its sat there until yesterday when I hooked up and ran TTS datamaster and found codes 15&26. I replaced the coolant sensor and the EGR solinoid and 15went away 26remains. I'm waiting on a evap soleinoid. The car fires up and runs fine. idles for over an hour, I can't get it to quit. I haven't driven it anywhere I want to eliminate all codes first. I assumed it was the opti again (#4) could these 2 codes actually cause it to act like it did? thanks in advance

shoebox

It could be a heat related illness, but if it were affecting the optical portion of the opti, you would probably get a code. Heat can also affect the ICM, but again, a code would be likely. To answer your original question, yes the opti can die without setting a code if the problem is in the secondary ignition portion of the unit. If that were to happen, though, it most likely would not start again.

I would be more inclined to say it is the fuel pump. It can exhibit the symptoms you describe. When it gets hot, it can quit. After cooling off, it can work again. Eventually it quits altogether. The only way to know for sure is to check the fuel pressure during the period the car won't start. You could also check spark at that time, to see if it is ignition related. Intermittent troubles are the worst to diagnose and often leave you stranded. You just have to be ready to check different things as they occur.