2000 Cadillac Deville Runs rough(idles) in park or stopped

I can think of 4 things right off hand that could cause this. I will answer in order of least expensive to most expensive.

1. Bad or unplugged vacumn line.
2. Idle Air Control ( IAC ) solenoid. ( Bad connection or bad solenoid ).
3. Exhaust Gas Recirculation valve stuck open. ( Could be just carbon builup, bad connection or bad altogether.
4. Cracked intake manifold or bad manifold gasket.

Let me know what you find and if we were any help, please contribute a little something for the cause.

[quote:4e49996729="jthomp"]Engine problem
2000 Cadillac Deville 6 cyl Front Wheel Drive Automatic 152000 miles
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Idles rough in park or while stopped in drive..."service engine soon" light blinks.

Thanks,

Jim[/quote:4e49996729]

scan the codes, off and down on the mode button, w/ key in the on position, its probally time to replace the coil packs on top of the valve covers. would be my guess