97 4 door 2wd 100k miles 4.3 v6 blazer wont turn over.

on freeway driving home engine seemed to almost choke on something like it was having an epileptic seizure. let off pedal back to normal for a couple seconds/minute increased speed slowly began choking again intermit spazzing. as i drove into driveway chokes seemed to hit almost violently then shut off... parked it in driveway dead ever since. assumed it was a fuel clog. checked fuel system at least what i am familiar with√.
key on 56-60 pounds fuel pressure√.
new battery~ charged√.
cranks but refuses to start. has good spark√.
wont turn over even when spraying starter fluid into tbody√.


took tank down clean and pretty√.re-installed√
busted stupid fuel vacuum gadget on top of tank replaced √

screaming punching and fighting a punching bag for like 2-4 hours√
checked pump while tank down√
reinstalled pump √
pump was replaced and perfect like two months earlier√,
replaced filters√,
lines√,
fuel pressure at 55-60 refuses to turnover.
spark good√

hooked up code reader could not get codes. sort of told me there were 5 issues but would not give actual codes.

told me:misfire, cat converter, 3 sensors_fuel oxygn & exhaust, but there are like 3 of each?which one?) a few days of dicking around with issues and disconnected battery at some point. did not realize 97s apparently erase all codes until running again? cant turn over to diagnose cant diagnose to turn over. good times.


a clue maybe? i had lost my gas cap and did not realize for a week or two and only noticed when tank needed refilling but could not or did not replace for another week or so when this occurred. gas cap still not on could this be part of the problem.?


i am stumped help? please thankyou