'99 seville dies at idle
 

My '99 SLS has been dying on me at idle after the engine is completely warmed up. Earlier, I got two codes to replace one O2 sensor and a Crank sensor. I bought both but a shop in town said that I only had one. Then I had a torque converter clutch code which was repaired(overhauled transmission). The problem persisted so I replaced the fuel filter and treated the fuel for water and used some injector cleaner in the fuel. No change. I checked the fuel pressure with the pressures low but within limits in a Haynes manual. As the engine warmed up, the needle on the gauge would vibrate about 3 psi total and got worse the warmer it got. So, I replaced the fuel pressure regulator. Tonight, I got the same thing. After about 20 miles of driving at a good cruise (and passing some slowpokes) with no problems at all, I pulled up to a light and it died again. Is there a Low oil pressure switch independent of the one for the dash light? My oil pressure light does not come on unless the engine is off. Where else can I turn? My troublshooting skills are getting a good test!

RE: '99 seville dies at idle
 

What about cleaning the IAC and throttle plate?

The oil pressure switch would only let it run for about 30 seconds before cutting fuel.

RE: '99 seville dies at idle
 

Also check the EGR to make sure its not carboned up