Need some help please
 

Hey all,
So I ask this question before but am still struggling to get a fix. I recently made some changes to my car 2015 SS 1LE in the rear and have thrown a bunch of codes. The codes came after I put the drag pack on. I have folks on here who stated they run the same set up with no issue. I’m running 17x5 with MT 305x45 in the rear and 18x5 28x 6 up front. The car had 315x34x 20 in the back and 20 in the front prior to the change. And as I stated above I did not have any codes before the wheel and tire change. The codes come in after you drive about a 1/2 mile and clear again once you turn off the vehicle and start it again. My guess is that if I by a buy a system like a flashpaq I can change the tire diameter and fixe the issue but the car currently has a tune in it that was there when I bought the car. I say all this to ask you if I buy the system and make these changes will it affect my current tune? The tuner that tuned it the first time isn’t far away but I don’t want to spend more money than I need to to just fix this issue and if I have to do that I’m going to go ahead and switch to E85 while I’m at it.

Thanks in advance for advice ( this problem is driving nuts)

What code?

Also, unless you're boosted or have raised your compression there's no reason to convert to ethanol. It literally makes no difference and you'll have to improve your fuel delivery system.

JoshNMN
The codes are T/C, power steering, abs, brake, stabilatrack. It’s interesting because the car drives normally. And I was not aware about E85 not doing much without boost. I do plan to add a supercharger later but not sure when that will be. Your right and it’s would be a waste to do it now.
Thanks

This may seem like a ridiculous question but, what shape is your battery in? These codes like to get thrown when battery condition is on its way out. Just a thought.

0stones0,
I thought that as well so I had it checked. They said it was good but needed charged. I charged it up and it did the same thing. But thanks for the comment. I’ll try anything at this point.

there's your problem you have 2 different size tires on yor car in height
the 305 45 17 is 27.8" tall and the 28 x 6 is 28" tall
from the tire calculator chart you have a 1.1 differance in size which will cause a 9 Rev/mile differance, that will give you errors in the abs,Stabiltrac and traction control systems

Spyderbuddy,
Thank you, So if I go in and change the tire size in the ECM it will correct the problem?

Don't Know maybe someone on here can answer that one for you

Yes if you ever change the tire diameter rollout circumference it has to be adjusted! All systems are computer controlled