Not that it isn't easy to stump me. Had this problem since two weeks after header install. EGR threw p0400 code, but I don't think that was the problem. After a few minutes of idle, the car goes into a cycle of the idle rpm dropping, running rough, then idle comes up and smooths, and a whirring sound is heard. Does this for several cycles until closed loop, then runs fine.

Now, I have changed the opti, and deleted the EGR and AIR with LT1 edit this morning. What is still active that is causing this? I am so close to having the car right. Should I pull the power to the AIR pump and see what happens?

TIA

 

I'm sure the whirring you hear in open loop is the air pump.

 

Even though I deleted it? I agree I just don't understand. Why is it bogging the car down, and can I disable it with no ill effect? Thanks shoebox.

 

Hey man, sorry to hear about all of your troubles. Whenever you get that thing running right, we need to get back to the track and see how bad it can beat me. Good luck with everything. See ya.

Bo

 

Hey Bo. I was gonna email you today. Actually, I am really close now. The opti was trashed and boy did a new one help. Gonna dyno tune this week. Just can't solve this last issue. Any ideas?

 

Did you just delete AIR from the car or did you remove the AIR system totally and clear up some space under the hood? If its what Im thinking and you havent already. I would ditch the whole AIR system, or just cut the power to it like you mentioned and hopefully that will help. Good luck with it!