Random flutter in AFR at idle whith logs, Help please lol.

[curtisdeville]

This program makes me feel real dumb at times... but are these the files you wanted me to post? These are the pids that I made for the vve logging when I started the tutorial. I dont have another calc_pids file in the config cause I replaced the original with the one I got from you. I also posted a log of the up and down afrs I am getting (Ithought at idle) throughout my rpms. I brought the car in to gm last year and they said they looked over everything and thought maybe it was just a bad tank of gas but it never went away. I also thought it was maybe from my long tube headers and high flow cats but the car has run like this since I bought it as far as I can remember. I did recently try and clear the ethanol readings, and the fuel trims to see if the computer would relearn a better way to idle lol. But like I said the random anoying flutter is gone

[joecar]

No worries, I understand learning curve.

Post your most current .ctz file.

Ok, I think the new clac_pids.txt is actually based on the old one (relating to VE/VVE) so you didn't lose anything.



What mods does car have beside long tube headers...?

And it was previously tuned (you said above)... for those mods..?

[curtisdeville]

"Camaro curt tune 1" is the current tune installed on the car now that is the original factory file with no mods except the I turned off the afm and the cat efficiency code we discussed earlier. I figured I would start fresh so I know what is done to my car and start fresh.

"Camaro Oakville no o2" is the file that I have been running since I had the long tubes installed. I brought it in to a shop that charged me 450 to "tune" the car to make adjustments for my aftermarket parts which include a K N cold air intake, flowmaster long tube headers, dual high flow cats, and a 3" flowmaster cat back exhaust. After the parts install the check engine light kept coming on and they turned out to be cat codes for bank 1 and 2 rears o2s but I cant remember off the top of my head exactly what codes. So he turned off the check engine codes and turned off the afm and said he would dial in my fuel tables but as far as I can tell its all untouched except the engine codes and afm.

[curtisdeville]

Took the car for a nice long drive today so the computer could catch up with the learning since i cleared all the pcm data and put the stock tune back in with all the mils that were shut off by that guy for my o2s to see if that would help with the idle afr. it didnt unfortunately and the o2 sensor codes obviously came back with a check engine light so i guess he did shut off the right stuff to make the car run without showing a check engine light for the rear o2s being to cold and far from the cylinders.

[curtisdeville]

Im read that some vehicles use the rear o2 sensors as well as the fronts to adjust fuel trims but im kinda sure this camaro does not since I read alot of posts about people having the get the rear o2s shut off after their long tne headers installed and they seem to not have a problem after. unless theres a way to actually completely shut remiver then from the pcms system instead of just turning off the mil reports?

[joecar]

I'm still looking at your tune/log.


The ECM uses the rear O2 sensors to perform trimming only in very specific circumstances, and I don't think you fell into that hole.

[curtisdeville]

I appreciate you taking the time Just bought some online courses from the tuning school cant wait to find the time to start em!

[curtisdeville]

I was taking more logs and shouldnt the front o2s be reading rich/lean semi simultaneously? Any chance that it looks like one is reading slow?

[joecar]

The front O2's should be cycling at at least 3 Hz, no slower.

Post a log file.

[curtisdeville]

Hey sorry I havent replied but I have been getting the car ready for the summer! Here is my wideband reading at idle, no check engine light....