L99, to tune or not to tune, that is the question
 

Well, I've ordered my new exhaust with off road mid pipes for my L99. From the manifolds back it will all be replaced, and I will be using o2 extenders to keep the CEL off while staying un-tuned.

I originally didn't want to tune because of my powertrain warranty. This is my first brand new vehicle and I'm scared something may go wrong if I tune it.

I have however, been leaning toward tuning to turn off AFM and turn off the rear o2 sensors.


Now my question, to tune or not to tune? Have y'all with L99's tuned out AFM and still getting 20+ mpg with no engine problems?

I won't be racing the car or anything like that, it will be a daily driver to and from work and a little into town cruising. I run 93 octane using shell gas or Exxon since they are on the top tier gas list.

I also will be changing my oil every 5,000 miles using Full synthetic oil, Royal Purple is what I have used with past vehicles (unless y'all suggest a better brand).


Any help would be greatly appreciated, I just want to be careful since I have no other mode of transportation to work. Also, the tuner I'm leaning toward is the touch screen inTune from diablo sport. Any better suggestions?

There is no question. Tune it.

Thanks K32 lol.

I really just want it to run correctly for thousands of miles to come.

It's a double edged sword for me,

I want to tune it because I'm afraid AFM may screw something up down the road with a lifter acting up

Then again I don't want to tune it so I can keep my warranty.

Although if I drive it like I do now, even without AFM, I might be able to stay above 20mpg.......maybe?

Afm only adds 1 maybe 2 mpg. It's not worth the headache at all. The drone headache that is, lol. I heard the SCTx3 is better and has more tables open for tuning.

Most problems will occur in the first 5-10k miles if you want to keep your warranty til then. It's not neccessary that you tune it unless you add lt headers or better mods.

Alright, i just hit 1,090 miles today lol.

I may wait till then before tuning it, unless the AFM annoys me too much from the new exhaust, then it may be sooner than later

Tune it, the afm noise through the exhaust gets annoying real fast.

I have over 20K on my truck since I had it tuned with no issues (knock on wood)


Ryan

I put over 20k on my tuned L99. Tune it and don't look back. :chevy:

Thanks y'all. I know it's not a guarantee that nothing will happen, but I wanted to make sure other L99 owners are having good outcomes.

SO as far as SCT tuning, which should I get? Pre-loaded or custom tuned?

Yeaaaaaa I got shitty mileage before the tune. Didn't notice a change at all after. Tune that sucker.

Haha, I hear ya man. I will do it then.

mine is tuned and i would not have it any other way

Thanks, I just cant wait to get my exhaust put on!! :happyanim:

Custom! The pre loaded tunes are pretty much worthless! Especially with an L99, get the trans shift points and torque management tweaked! I got my SCT and custom tune from Ted Jannetty. He'll work with you to fine tune the shift points and he'll tell you if you need to datalog for fine tuning!