hey guys I am new to the forum, looking for any suggestions, I have a 1997 Lexus es300 with 200K, I had issues with it running rough. engine codes at that time where P1411 P0402 and P0300, I then replaced my EGR valve, all codes stayed off for about 15 min till the engine got warm, it started to run real rough at idle, very hesitant when you go to take off from a stop. I disconnected the vacuum line that has the vacuum serge tank on it, and the car runs fine. I thought maybe that line was plugged so I replaced the vacuum serge tank, when its hooked up to the ERG it runs rough, even with the new one installed. once I remove the vacuum line to the erg it runs good, when it is running rough I have been trying to drive it around home, but It wont throw an engine code, I am unsure to where to start, if anyone has any suggestions or help I would greatly appreciate it. Thanks

 

Hello,

What brand did you use for the replacement parts?
Are you sure there are no leaks at all around the EGR?

The problem is that EGR should be disabled on idle, meaning that it should not matter if you will take the hose off of it, since there should not be any vacuum in it. See if you have leaks around the EGR valve, and then make sure that the Vacuum Switching Valve for the EGR system is working properly by applying 12V to it.

Hope this helps and best of luck!