Hockeyfun1

I have a 2022 HTC and it originally had the NPP exhaust. I then bought a Borla ATAK. I was getting a clicking noise when it was switching from V4 to V8 and was told by Borla that it's a bad actuator and my exhaust needs to be replaced. They replaced it under warranty and were great to deal with. The new exhaust started making the same noise too, even though I did the relearn at the dealership. Borla recommended getting another relearn and it seemed to help for a couple days but the noise is back when it's cold (before it did it all the time) and I just got another CEL when I hit Z mode to switch it to V8 only. I don't know how to check my CEL, since I didn't see it on the mychevy app. Borla, who as I said has been great, said if the noise comes back then the exhaust isn't right for the car and they'd have to have me send it back and refund me.

Has anyone else run into this issue? What should I try next? I still have my original exhaust but I don't know if it will just bolt back on or if it needs additional pieces. Or should I try a Corsa or does my car just not like aftermarket exhausts and I'll run into the same issue?

Kracka

Any auto parts store can check the code for you. Some cars require repeating the relearn procedures 2-3x to fully stick and work permanently. Sounds like it's getting better, so hopefully one more time does the trick. My car (2021) required it twice, while I had to do a local buddy's car (2022) thrice.

I'd suggest this scan tool so you're able to do all this yourself:

Hockeyfun1

Any idea why it would require repeated relearn procedures? Would I have to do it 2 or 3 times then never again? Or maybe again in a year?

Kracka

Edited my post above with a little more info. The newer ECUs seem to be getting more sensitive, and at the same time the new Borla valves are wearing in (some are tighter than others). I've never had to do a car more than 3 times, then they're good to go permanently.

sTz

I agree w/Kracka in purchasing the bi-directional scan tool and doing it yourself. I installed the Borla ATAK on my ‘24, and did the valve relearn without any issues. I’ve read that some dealerships are just clearing the code and not actually performing the relearn. Not saying that’s what they’re doing, but at least you could rule that out, which is a lot less hassle than removing the exhaust again. Also, you can pull up the CEL code and clear it on the scan tool. So it does more than just the relearning function.

SMOKN C8

You can get the scan tool from Amazon for like 120 bucks(on sale) and it literally takes seconds to do the relearn once you enter the menu.

Honestly, dealership shouldn't even be charging people for this. If I'm ever at a car show in the DMV/NOVA, and anybody needs it done, I will absolutely do it for them for free.

Avanti

Yes, first buy a reader. Every parts store has them, and they cost little. My Autel I bought years ago came with a very good manual, as well. However, were it me, I'd put the original exhaust back one with all new gaskets and call it a good learning experience, since you can get your parts outlay refunded. Many such reported here don't work out that well. All the best, in any event.

Hockeyfun1

My CEL has always been exhaust related anytime it's popped up. Will the relearn solve the CEL issues?

I thought I normally get an email or can check in the app why I have a CEL? Most places around here have a "broken" reader aka they don't want to waste time reading any codes because they'd rather be on their cellphone.

Kracka

Yes, the relearn procedure, when finalized, which solve the CEL issue.

I'll do it for anyone who needs it in the DFW-area.

Hockeyfun1

Another thought, but maybe I'm crazy. After each time I've gotten a relearn, the exhaust sounds quieter. When it starts making the V4 to V8 noise or throwing a CEL is when the exhaust seems louder then. Thoughts?

Kracka

The valves are likely no longer closing as the ECU sees them out of range. We experienced that on my friend's 2022.

SMOKN C8

I have never heard of a particular car, not liking aftermarket exhaust. As long as you have the right system for your car, it's just a matter of getting the right person to do the installation, and then the relearn on valves (or use simulators).

Hockeyfun1

So would the relearn tool that was linked likely fix this and give me the proper noise out of the exhaust? I remember it being obnoxiously loud, which is what I expected and wanted from the ATAK, but after having the dealer do the relearn, it was much quieter.

Also do I do the relearn with the Amazon tool, then do it again and again? Or just wait until it starts acting up again?

SMOKN C8

I would only do it when it’s needed, but it literally takes seconds to do once the tool is connected

Wormwood

I have a theory on the relearning not working. The best I can figure is the exhaust valving is getting in a bind at once up to temps. I.e. you have the exhaust relearn performed when the exhaust is cold however once it warms up the valves get bound up & when going into V4 mode the ECU detects the valve binding as at the end of travel, but it's either occurring to fast or the valves are stuck in either position & can not move. I'd suggest a high temp grease or something maybe graphite on the actual valve hinge. Any case you might try relearning when the exhaust is hot....

A detail of the relearn process goes something like this....

With the exhaust relearn process the ECU detects the end of travel of the valves from the current draw of the actuator motors, once the motors reach the end of travel the current draw spikes & the ECU marks that as the end of travel. This is a cheap way of using DC motors instead of stepper motors. So the ECU has recorded the current draw while the valves are in transit, time in transit, & the current draw once the valves hit the end of travel. In the case of the OP the valves get in a bind it doesn't match up with what the ECU is expecting, so it throws a code....

Most of these exhaust systems seem to work thru any binding issues as they break in....YMMV.

Wormwood

Bluehinder

Honestly, the older I get, the more I try to just live with the oem stuff. Fewer headches for minimal gains. Who needs the brain damage.

Sorry to hear OP.

449er

Go back to stock & be done with it

Mrchen

I bought the Paragon Touring system, has Cicio install it, not one code or one problem ever

Hockeyfun1

I did the reset. Any idea why all these codes popped up when I hit the Z mode button originally? Some don't seem relevant to the exhaust.

I did the relearn and cleared the CEL. My question is should I have been in Z mode and did the relearn or not? I kept hitting Z mode when I was on that screen and saw the valves on the screen go from open to close. It didn't give me any sort of confirmation that the relearn was done. Not sure if it actually was, or if that's just how it works?

I went for a drive and it sounds a little noisy when cold going from V4 to V8 but then it quiets down. Is this normal?

Hockeyfun1

I tried it again. I noticed the last two times when the engine and car is cold, I get a nasty rattle when it's in V8 mode and about to go to V4 mode. The rattle goes away once the engine is warmed up. It never did that noise before, it did the typical stuck valve noise that was a lighter more constant rattle.

So I did the relearn again when the engine was 205 and oil was 196. I'll see if that makes a difference. Should I be in Z mode or not? When I'm in Z mode, it says open, when I turn Z mode off, it says closed. What mode should I be when doing the relearn?