05' C6 LS2 Corvette Tuning Help

[OGGKillerPoodle]

Hey Guys, currently new to tuning and to forums. I am working on learning both quickly.

Stats and equipment: 2005 C6 Corvette Z51 stock except for a Vararam intake, HPTuners MPVI 2, AEM wideband 30-0310 (in-line model)

Here is my issue: I am following along with Goat Rope Garage's MAF Tuning https://www.youtube.com/watch?v=7IoWmLEmlvE&t=472s but every time I write to the ECU and start up the car, it runs absolutely god-awful. I followed the directions in the video to put it into open-loop and make all the changes. My wideband says it's idling at 1.5 Lambda but I can't figure out why it's such trash. In the video, Kyle's first start is a little lean at 1.15 Lambda, which he fixes by changing the fuel table by 1.15. I tried to do the same to mine (by multiplying by 1.5) but it's still running like crap.

Now my battery is dead and the HPTuners Scanner is forgetting the wideband is there, so it's time for me to get advice from the pros online. I'm pretty frustrated. All I'm wanting to do is get a little more power out of the Vette. Should I just be paying someone to email me a tune and then try to tweak that myself?

Thanks for the help.

[5FDP]

Post the tune file you are using and any logs.

[kevin87turbot]

Hey Guys, currently new to tuning and to forums. I am working on learning both quickly.

Stats and equipment: 2005 C6 Corvette Z51 stock except for a Vararam intake, HPTuners MPVI 2, AEM wideband 30-0310 (in-line model)

Here is my issue: I am following along with Goat Rope Garage's MAF Tuning https://www.youtube.com/watch?v=7IoWmLEmlvE&t=472s but every time I write to the ECU and start up the car, it runs absolutely god-awful. I followed the directions in the video to put it into open-loop and make all the changes. My wideband says it's idling at 1.5 Lambda but I can't figure out why it's such trash. In the video, Kyle's first start is a little lean at 1.15 Lambda, which he fixes by changing the fuel table by 1.15. I tried to do the same to mine (by multiplying by 1.5) but it's still running like crap.

Now my battery is dead and the HPTuners Scanner is forgetting the wideband is there, so it's time for me to get advice from the pros online. I'm pretty frustrated. All I'm wanting to do is get a little more power out of the Vette. Should I just be paying someone to email me a tune and then try to tweak that myself?

Thanks for the help.

With a stock car with just a Vararam, you shouldn't have to multiply the MAF curve by 1.5. The stock curve should be within 5% or so. If you need to add 5%, you just multiply by 1.05. If you need to subtract 5%, you just multiply by 0.95.

[OGGKillerPoodle]

Post the tune file you are using and any logs.

What things do I need to log for it to be useful?

[OGGKillerPoodle]

Post the tune file you are using and any logs.

With a stock car with just a Vararam, you shouldn't have to multiply the MAF curve by 1.5. The stock curve should be within 5% or so. If you need to add 5%, you just multiply by 1.05. If you need to subtract 5%, you just multiply by 0.95.

Which is why I'm confused that the AEM wideband is showing lambda 1.5 when it should be closer to 1.0

[kevin87turbot]

Which is why I'm confused that the AEM wideband is showing lambda 1.5 when it should be closer to 1.0

Where is the wideband sensor located?
This config should get you started.
2009CorvetteList.Channels.xml

[pannetron]

1.5 is dead lean so I'd suspect your WBO2 sensor is getting fresh air mixed with engine exhaust at idle.

[OGGKillerPoodle]

Where is the wideband sensor located?
This config should get you started.
2009CorvetteList.Channels.xml

I swapped the stock o2 sensor on the driverside with the wideband. I wanted to get an extra bung welded for it, but my welder guy said it was impossible to put one before the cat with the stock headers.

I put the engine into MAF open loop so that it's not freaking out about no input from the stock o2 sensor btw.

[OGGKillerPoodle]

1.5 is dead lean so I'd suspect your WBO2 sensor is getting fresh air mixed with engine exhaust at idle.

That's a good point. IDK how it would be getting fresh air though.

[kevin87turbot]

That's a good point. IDK how it would be getting fresh air though.

How does your car run with the stock MAF table in it?

[GHuggins]

Post a log with it in closed loop "ie car controlling fuel trims" showing the wideband readings. If it's close to 14.7 to 15.5 then your wideband should theoretically be reading correctly. Of course that all depends on whether or not your car is correct, but will at least show you it's close. CATs go through burn offs that will skew afr's. You could even possibly have the exhaust leaking past the wideband and having it suck air back in skewing the widebands readings - does it still show lean with throttle?

Then when's the last time you did a wideband burn off? This is where you leave it plugged in hanging out in fresh air before performing a recal...

Finally after everything's said and done, with proper cautions being taken in the tune, you can actually tune your car entirely without a wideband with those few of mods, so up to you how much you really want to fight it...

[OGGKillerPoodle]

How does your car run with the stock MAF table in it?

It runs okay. Not great, but not bad.

[OGGKillerPoodle]

Post a log with it in closed loop "ie car controlling fuel trims" showing the wideband readings. If it's close to 14.7 to 15.5 then your wideband should theoretically be reading correctly. Of course that all depends on whether or not your car is correct, but will at least show you it's close. CATs go through burn offs that will skew afr's. You could even possibly have the exhaust leaking past the wideband and having it suck air back in skewing the widebands readings - does it still show lean with throttle?

Then when's the last time you did a wideband burn off? This is where you leave it plugged in hanging out in fresh air before performing a recal...

Finally after everything's said and done, with proper cautions being taken in the tune, you can actually tune your car entirely without a wideband with those few of mods, so up to you how much you really want to fight it...

1. So this may present an issue, I have been using one of the factory O2 bungs for the WB. Afaik it runs like crap in closed loop with only one O2 sensor.

2. Honestly I was too scared to even give it any throttle so I have no idea if it is still lean or not.

3. Never heard of doing a burn off for O2. I will have to try that and then recalibrate it with the default resistor mode.

4. That's awesome to know that if all else fails I can just tune it w/o the WBO2. I may end up doing that because all I want is the engine to be a lil more powerful and efficient.

[blindsquirrel]

My opinion, though I know others agree with this too, is that if the intention is to have it full-time forever in open loop, then do all of the tuning in OL with the wideband. BUT, if it's going to be run in closed loop with the stock narrowbands in control, then the closed loop portions should be tuned using the stock narrowbands. WB can (should) still be used but only for tuning the OL/WOT areas.

O2 sensors do wear out and have a recommended replacement interval similar to spark plugs. If you don't know how old they are (or if you know they're the originals) it's not a waste of money to replace them before investing a bunch of time in using them to tune with.

[GHuggins]

If memory serves you have to leave it hooked up and turned on while out in fresh air for about 2 to 4 hrs. For reference Labs will do "overnight" burn offs. I think my lambda pro even has it in their operators manual for "cleaning" the sensor...

So your using a pre-cat O2 bung then? I thought you were using a post cat bung. You should be able to disable dtc's for post cat and be good to go. You might even have a misfire on that bank throwing things off due to miss-fueling...

Nearly every NA car I tune, I'll tune with O2's only. This is mainly due to rd tuning right now, but never the less it's rather easy to do and really close when checked with a wideband. With timing pulled out and using common sense you can just about dial your VE and MAF tables in after a couple of revisions and then minor tweaks after that.

[OGGKillerPoodle]

Update:

Thanks for the advice guys, I got it figured out finally.