2000 Lumina Rough Idle Question
 

Whats up guys Have a question about my Idle on my 2000 3100 Lumina. A little back info first. I recently did a bunch of repairs on the car about 3 weeks ago because I had a TPS code, and Low voltage EGR code. Car drove perfectly fine but needed repairs for emissions. So I put in a new TPS, Cleaned out the EGR port and tossed in a new EGR as well as changed the EGR harness plug. I got rid of the codes by pulling and exciting the ECU/BAP fuse and driving the car for a week to run all its cycles. Took it for emissions check and car passed with no problems. Now I primarily use this car only for coming and going to work which is all highway driving. I now have to do some street driving twice a week taking my daughter to my in laws house. Do to a lot of stop and go traffic I have noticed the car has a idle flutter and buckles a bit when at traffic lights. Sometimes it does it a little almost like a hiccup and other times its very erratic. I noticed that it doesn't happen when I first start driving it but more after the car has been driving around for a while and making frequent stops. I also noticed that It seems to do it more while in Drive with the foot on the brake then in park. I decided to pull the IAC and clean it with a wire brush and some carb cleaner, As well as the port it goes in. I thought it fixed the issue because it didn't do it the last few times after I did this. But today I noticed it again and actually recorded it with my cell lol It was so bad that my headlights, Dash and interior lights were dimming in and out. I don't know if there is a Idle relearn that needs to be done or if that's even possible being this is a OBD2 car, Can it be that maybe the IAC is just bad all together or could it be something else. Im kind of ruling out plugs and wires since it doesn't break up while driving. Also I don't notice any vacuum leaks that I can feel or hear. Maybe it could be the primary O2 sensor? Idk, I haven't really got crazy with diagnosing since its been hit or miss with the issue.



FYI I FORGOT TO MENTION THERE IS NO DTC CODE PRESENT

Any guidance would be great, Because I am truly getting tired of wrenching on this car. Between the current issue and issues it had including Having to change my upper and lower intake gaskets 2 years ago its getting old. I know I will figure it out but I rather get pointed in the right direction instead of playing trial and error until I resolve it. The car runs Pretty damn good for having 158K miles other then this problem and the annoying piston slap lol... I hate these touchy 3100/3400's, LSX motors are more my thing :D


Thanks guys, Phil...

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