This all started when I had a CEL come on for my EGR. So, I checked some of the vacuum lines near the EGR and low and behold they were disconnected. I plug them in and the CEL gets reset.
A couple of weeks later is comes back in for the same issue P0403, IIRC. All of the vac lines are still connected. Currently, the light is off, but the code is stored.

My issue is with the idle. When driving and coming to a stop, my wideband shows that my AFR is at 17+ for maybe 20 seconds before going back to a normal ~15.

Could this be because the EGR needs to be replaced, or is this idle issue due to something else?

Also, the car has had the same tune for years.

 

My idle isn't stable either but it's not effecting anything. It bounces time to time. Must be an evo thing. Double check the lines for holes. I doubt you have to replace the egr but I'm sure you can find one cheap or just delete it.

 

This never happened before, so Im not sure if it is an evo thing. Does yours do this every time when coming to a stop and disappear after a short time?

 

i wissh to know also.i have the same exact problem.no cel no codes but acts like that.