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

[curtisdeville]

Hey guys, my name is Curtis and I am new to the site and tuning. I purchased the Efilive V2 about a month ago and have been reading up on tuning and buying movies and books ever since, I originally bought the V2 so I could have a tune for my lmm sent to me and I could update the ecm myself and I am a Chevy enthusiast to the max so figured I would learn to work on the tuning aspect of my car on top of the joy I take in upgrading the mechanical parts. Anyways I had my 2011 Camaro SS with the 6.2l auto and E38 ECM tuned last year by a local shop here in hamilton and now that I have the materials I need to look into my car I see that he only turned off the codes for my o2s so my for my headers and shut of the AFM but didnt touch any tables. I did a comparison with a stock file I downloaded and the tables are stock. Since he "tuned" my car though it is running rich (I can smell the fuel) and I get a random "flutter"in the engine only once when I am sitting say at a stop light, idling, and it seems completely random. Sometimes it happens and sometimes it doesnt. So I have attavhed the ECM file and a log of a drive I took that I happened to catch it on. The short term and long term fuel trims seem to pause before and during this time and the AFR goes from 14.68 down to 12.44, up to 15.96 and back to stoich all within about 5 seconds and I can hear the engine going through this. I am worried the When my Wideband comes in tomorrow and I set everything up to adjust my VVE, that if this happens it will hit a point, even for a a couple seconds, that is too lean or something else. Does anyone know or can you see what is going on here? I really appreciate the help and am enjoying the slow process of learning to do this stuff. Was just hoping not see see something weird like this before I go and follow the tutorials to do my first tune on my car. Also on a side note, can I follow the tutorial for idle tuning an ls1 that is pretty popular in these forums for my l99/ls3, is it pretty much the same process. Thanks guys, this is my first post and I hope it doesnt make me look dumb lol.

[joecar]

That fueling flutter you see is the catalyst efficiency test running...
( it looks like you don't have cats, or they're alot not working )
if you want to disable it see C1701.

[joecar]

From the set of pids you log, remove these (they're either the wrong ones):
- GM.AFR
- GM.TP
- GM.IBPW1/2
- CALC.INJDC1/2
- E38.AFRATIO (we're going to use SAE.LAMBDA instead; in light of alcohol content in gasoline, we want to avoid using AFR).

Log these instead:
- GM.ETCTP
- GM.INJPWB1/2
- CALC.INJDCB1/2 (see attached calc_pids.txt file)




Attached calc_pids.txt file: copy this to this folder: C:\Users\you\Documents\EFILive\V7.5\User Configuration
and rename it to: calc_pids.txt

calc_pids--E38-1WB.txt

[curtisdeville]

Thank you sooooo much. Im gonna try that tomorrow, I really appreciate the replies. I have hiflow cats on since my long tube header install and brought it in to get the rear o2 codes tuned out and the mil light is off but it has ran rough ever since.

[joecar]

I forgot to attach a pic of your log showing the catalyst efficiency test...

it where lambda goes down and then up.

[curtisdeville]

Log_0003.efi

Changing that code did help a ton and i cannot notice the "flutter" now!

My idle still feels like it going up and down constantly though just without the "flutter it was doing here and there. I do have long tube headers and high flow cats installed, and I am not sure if the idle issue is being caused by the o2s or not. The tune had the rear o2 mils shut off and now the cat efficiency testing off as well but I finally got my wideband in and although the car is commanding 14.68 the wideband is reading a constant up to around 15.4 and down to 13.1 or lambda 1.090ish and 0.950 if i remember right. I took another log with a different pid set with the car at idle, some smooth driving, a wot run and back to idle when I parked.

You guys dont understand how much I appreciate the time you took to look at my posts and if you could check it out one more time I wont bug ya again..... maybe lol. I am just really excited to get some good logs and start going through the tutorials but like everything else I do I have hurdles to get over before I can get going.

The car was sitting for a while so when I took it out last week I ran it dry and put some clean and new 94 octane in it and cleared the computer since my battery did get low while sitting. ps the car idled rough last year before I put it away and gm said it was fine when I took it in and had no codes nore any maintenance or visual issues. They thought I got a bad batch of gas but unless I got the last 20 tanks bad thats not my issue. Anyways if you could take the time to look at my log and see if everything looks normal or if maybe the headers are messing with the computer or I was thinking maybe one of the rear o2s was gone bad but my understanding is that the car doesnt use the post for fueling anyways. thank guys.

[curtisdeville]

Also I already did the calc pids file change as per the vve tutorial on here but I replaced it with the one you sent anyways but what does that file do? Am I supposed to open it in the scan and log as a pid file or something? or is it just a background setting.

[joecar]

The calc_pids.txt file defines calculated pids that appear in the V7 scantool.

Post your vve calc_pids.txt file, we need to merge the new calc_pids stuff into it.

[joecar]

Log_0003.efi

Changing that code did help a ton and i cannot notice the "flutter" now!

My idle still feels like it going up and down constantly though just without the "flutter it was doing here and there. I do have long tube headers and high flow cats installed, and I am not sure if the idle issue is being caused by the o2s or not. The tune had the rear o2 mils shut off and now the cat efficiency testing off as well but I finally got my wideband in and although the car is commanding 14.68 the wideband is reading a constant up to around 15.4 and down to 13.1 or lambda 1.090ish and 0.950 if i remember right. I took another log with a different pid set with the car at idle, some smooth driving, a wot run and back to idle when I parked.

You guys dont understand how much I appreciate the time you took to look at my posts and if you could check it out one more time I wont bug ya again..... maybe lol. I am just really excited to get some good logs and start going through the tutorials but like everything else I do I have hurdles to get over before I can get going.

The car was sitting for a while so when I took it out last week I ran it dry and put some clean and new 94 octane in it and cleared the computer since my battery did get low while sitting. ps the car idled rough last year before I put it away and gm said it was fine when I took it in and had no codes nore any maintenance or visual issues. They thought I got a bad batch of gas but unless I got the last 20 tanks bad thats not my issue. Anyways if you could take the time to look at my log and see if everything looks normal or if maybe the headers are messing with the computer or I was thinking maybe one of the rear o2s was gone bad but my understanding is that the car doesnt use the post for fueling anyways. thank guys.

Post your current tune file, let's take a look...

[curtisdeville]

Hey joecar I actually posted a reoly before my last with a new log and bunch of info about how that did fix the random flutter but my wb i finally received is still reading and rapid uo and down in lambda at idle that i cant hear in the engine. i have high flow cats and long tube headers and am wondering if that when theyinstalled these it messed uo my o2s or if its something else but anyways ill repost them as soon as i get home as it didnt oist for some reason alomg wiht my pids file thanks again ! your awsome!