Cutting out on top end??
 

Hey, new to the site. I just bought a 2015 ZL1 with only 6900 Kilometres. The list of mods it has:
-borla long tube headers
-cold air intake
-borla x pipe Offroad racing with cat deletes
-Diablo custom tune to stop o2 sensors for cat deletes and increase fuel pressure
-underdrive pulley for supercharger boost up 30-40% above stock from Lingenfelder

i was passing a car on the highway today in 6th gear around 3500RPM and the car just cut out almost like it was losing fuel, I don’t think it was a misfire because I had no check engine light come on. Tried a few more pulls after and it did it again in 5th gear.

I checked for codes and there is 2 codes stored,
P2097
P2098

Fuel Trim lean for Banks 1 & 2.
My suggestion is remove the Diablo custom tune program, go back to OEM program.
Get a OBD2 reader and see the value of O2 sensors.

The problem is the tuner didn’t come with the vehicle. Previous owner traded it in on a truck and didn’t leave the tuner. This was the info I got from the salesman. I tried getting the previous owners name but the dealership wouldn’t give it to me.if you look at the codes its actually lean on one bank and rich on the other.

Either find a tuner and have them remove present program and go back to OEM program, find another PCM from salvage yard, or visit a GM dealership and have them install OEM program.

Speed must be fast, aka, 3500 RPM in 6th gear, 50% overdrive, has got to be quick.

I found the original owner and purchased the tuner from him. Is a tune ever required with the mods I have? I think oem program should be fine.

Should be fine with OEM program. Try it.

I Put the original tune back in took it out for a drive and the cutting out issue is now gone, but now I seem to have a slight misfire on top end. Totally different than what I had before.

I had the same issue on my 2021 SS after tuning my PCM, tried adjusting the cam timing and it actually made a pretty big difference, now I'm seeing a solid 20mpg on the highway vs 17 without those adjustments.

I've noticed similar issues with the 2022 Camaro SS, could be related to a faulty tune or faulty sensor, but I've also read some owners swapping cats and seeing gains up to 30-40hp.

Hey guys, I've been noticing on my 2021 SS that at high RPMs, especially in 6th gear, the engine seems to dip out a bit on the top end - it's defintly not pulling as hard as it does in lower gears, or even 5th at 5500+ RPM. Anyone else experience this, or is it just me and my tunes?