2002 Cadillac DeVille Q&A
2002 Cadillac DeVille Question: rough idle
Here is a ton of great information about the P0300 code: http://repairpal.com/OBD-Code-P0300 - Bret Bodas
Try the Vacuum Hose's or Brake Booster. - Visitor
The EGR valve may stick open, causing a rough idle and/or the Check Engine Light to illuminate.
rough idle at start up. runs okay on road
In addition when first started there is no power brake assist. I have to rev the engine to get the vacum to build. The engine seems to run fine above 1500 rpm and drives fine on the highway. Sugge...