Ruptured fuel rail pressure sensor diaphragm. Start by inspecting the intake vacuum reference line for raw gas. Also check for vacuum leaks in the intake vacuum reference line.
Would help to monitor and cross check the fuel pressure as reported by the PCM against and external gauge. We want to see if the PCM reported fuel pressure stays around 40 PSI where as the gauge pressure varies.
Would help to monitor and cross check the fuel pressure as reported by the PCM against and external gauge. We want to see if the PCM reported fuel pressure stays around 40 PSI where as the gauge pressure varies.
I just recently had the same issues as you for about a month. i thought i had ruled out my fuel pump also. everytime it would run bad it threw a whole list of codes including p0190 i would erase them retune my car it would run fine for sometimes 1 mile and sometimes a 100 miles. I troubleshooted everything from tps, frps, ignition coils, spark plugs, vaccum leaks. I then replaced my fuel filter and still nothing. Finally i replaced my fuel pump and runs like a champ again. i was told fuel pumps will sometimes go out in stages causing it to run and idle off and on like this. I know it sounds like it would not be the pump because when you retune it does just fine sometimes but i reccomend it. I was also told because of low fuel pressure it would throw all the catalatic codes, to lean codes, and frps code because they are all reading wrong when this drop in fuel pressure occurs. Sorry horrible grammar but hope it helps.