LS7: AFR issues

[C6Z_sd]

Please take a look at the scan and tune. The WOT runs in the scan are at 3:53 and 5:51. I'm not concerned with the 1-deg of KR in the first run. What I am concerned with are the significant dips in AFR (11.4-11.6) in the 4100-5400rpm range, where commanded AFR is 12.2-12.5. The airflow also seems to peak (directly proportional to the AFR and injector curves).

Is there a possibility the ECM is looking somewhere else (not the MAF Hi table) or adding a correction factor? If so, any ideas where the ECM is looking?

Mods are in the signature; almost stock, with bolt-ons. This is street tuning, so I don't know how it affects power, but seat-of-the-pants and speed curves appear to have no effect (it feels smooth all the way up).

Looking forward to some insight...thanks in advance.

[TARANTULA]

I'm having the same problem. I was thinking maybe is related to MAF turbulence. today I will try my stock intake and see how it looks.
(I have the same mods but no headers)

[C6Z_sd]

I was warned not to buy the Halltech due to excessive turbulence at the MAF...maybe I should have listened. I bought it anyhow, because it posted the best dyno numbers.

Anyone else with the Halltech with this problem?

[carlrx7]

disable maf and tune ve

[DSteck]

Halltechs have no issues. I'll look at your stuff later.

[Higgs Boson]

I run a Halltech, it's fine.

You need to disable Cat Over Temp (COT) while tuning. Your cats are probably heating up in that high cylinder pressure RPM range and it's adding fuel. I would also zero out your AFR Correction Spark tables and tune spark in the main table, IMO.

[TARANTULA]

Well gave this another try but still get the same results. One run it runs lean I correct using Mult by half then the next run is rich. I'm having a hard time making the car run consistant 12.40's. I will do another free air test to rule out the wideband. and maybe try the stock intake.

[Higgs Boson]

You also need more hits than 2 or 3, make a few passes to get better data, also make sure your LTFT are disabled in case they are carrying over into OLWOT.

Also make sure COT is disabled.

Apply your changes to expanded decimal places and smooth (like posted above) with expanded decimal places.

[rynez06]

Please take a look at the scan and tune. The WOT runs in the scan are at 3:53 and 5:51. I'm not concerned with the 1-deg of KR in the first run. What I am concerned with are the significant dips in AFR (11.4-11.6) in the 4100-5400rpm range, where commanded AFR is 12.2-12.5. The airflow also seems to peak (directly proportional to the AFR and injector curves).

Is there a possibility the ECM is looking somewhere else (not the MAF Hi table) or adding a correction factor? If so, any ideas where the ECM is looking?

Mods are in the signature; almost stock, with bolt-ons. This is street tuning, so I don't know how it affects power, but seat-of-the-pants and speed curves appear to have no effect (it feels smooth all the way up).

Looking forward to some insight...thanks in advance.

is your commanded afr changing??