Car dies at Idle

So yesterday I got the dreaded p2004,5,12 error codes again (get them on and off for the life of the car) I clear the code and for some reason two things happen when I clear the codes.. One it is hard to start the next time I start it and also when I am driving and push the clutch in to come to a stop, it either almost dies or does die. Usually this goes away in a few days. Does anyone know why this would happen? The car has uppipe (Sti) and a DP and muffler deletes. Other than that bone stock. 66k miles on it and I am seriously thinking about trading it in on a Yaris.

Hard start happens after you clear the ECU.... that's normal

 

 

Have you taken this into the dealer ever? You have a faulty Tumble valve.

yep. I even left the code in when I showed it to them. And they said it was a phantom code But they knew about all of them. I never really got decreased power etc. But the dieing at idle pisses me off. Could the tumbler be causing that?

sounds like the tuble valve broke off or something is stuck in it. You've also decreased your backpressure a ton without telling the ECU, that could cause some problems

vacuum leak is another area that will cause a car to cut off at idle. if the tube is intact, maybe look for a vac hose that has come disconnected....

sounds like the tuble valve broke off or something is stuck in it. You've also decreased your backpressure a ton without telling the ECU, that could cause some problems

 

Yep decreased backpressure somewhat. The resonator is still in. However why would it only do this when clearing a code? I didn't reset the ECU just deleted a code with my OBD Reader.

 

 

Same thing with the intake. I would expect it to continue until fixed if related to a vacuum tube coming out. But it seems to only do it for the first couple days after I delete the codes.