Runs fine for about 15-30 sec on start up then revs up and dies. Fine once driving. Was told by Zzp it was o2 sensor even tho no engine codes. I replaced it and still same problem. Engine trans have less then 30k on them. No codes showing need help?

 

Check your fuel pressure at the fuel rail..
Could be clogged fuel filter or failing fuel pump.
Check/clean the IAC..(idle air control)

 

Also it can't hurt to take the mass air flow sensor out and clean it up with some maf cleaner.

 

Cleaned the maf didn't help. What is required to check pressure at fuel rail? Fuel filter is new. Possibly on the pump never replaced that and it is maxed out on my set up