[FoundNemo]

The fuse pull. Let's discuss just that. Sorry the other stuff was irrelevant here I think.

[gotswap]

for the below, just take the fuse out and no CEL at all

Exhaust - Unplug the NPP valves in the rear, cover the connectors (male and female) with electrical tape and zip tie them up. There will be no CEL (soft code only for NPP valve not functioning, but no light). Results are a nice tone with little to no drone at all at all times and more pops and gurgles throughout the rev range. Very good sounding. Also noticed a very nice throttle response gain at part throttle in all modes, no change at WOT for power/etc though. If you look at the inside of the NPP mufflers (pics online) for 17+ you can see that when the valves are closed, there is an extremely convoluted and poorly flowing pathway for the exhaust which likely is what causes the throttle response drop, as compared to an open valve. You can always plug them back in from time to time to avoid "sticking" for the valves. Do not unplug the fuse 51 or you are likely to have erratic issues and CEL codes fyi (unlike previous gen ZL1's where this worked fine I think).

[FoundNemo]

Originally Posted by gotswap

for the below, just take the fuse out and no CEL at all

Exhaust - Unplug the NPP valves in the rear, cover the connectors (male and female) with electrical tape and zip tie them up. There will be no CEL (soft code only for NPP valve not functioning, but no light). Results are a nice tone with little to no drone at all at all times and more pops and gurgles throughout the rev range. Very good sounding. Also noticed a very nice throttle response gain at part throttle in all modes, no change at WOT for power/etc though. If you look at the inside of the NPP mufflers (pics online) for 17+ you can see that when the valves are closed, there is an extremely convoluted and poorly flowing pathway for the exhaust which likely is what causes the throttle response drop, as compared to an open valve. You can always plug them back in from time to time to avoid "sticking" for the valves. Do not unplug the fuse 51 or you are likely to have erratic issues and CEL codes fyi (unlike previous gen ZL1's where this worked fine I think).

Removing the fuse can cause issues and CEL's in many instances for 17+ ZL1's, my buddy's car did after a period of time and he had some erratic throttle issues as well (A10 car). Google around. Unplugging the actuators does not (as referenced by the many aftermarket non-NPP compatible exhausts that require unplugging them).

[ICTsccaCamaro]

Originally Posted by FoundNemo

Removing the fuse can cause issues and CEL's in many instances for 17+ ZL1's, my buddy's car did after a period of time and he had some erratic throttle issues as well (A10 car). Google around. Unplugging the actuators does not (as referenced by the many aftermarket non-NPP compatible exhausts that require unplugging them).

My fuse has been pulled on my 18 for 2 years with no issue

[FoundNemo]

Originally Posted by ICTsccaCamaro

My fuse has been pulled on my 18 for 2 years with no issue

Doesnt change the nature of the post. If folks comfortable trying it out, go for it. Either way, the post is about a set of free mods. Moving on..

[gotswap]

Mine was pulled with stock exhaust for months, no issues. It is free and quick and easily reversible, those connectors are kind of a pain to get at.

[crosive]

Originally Posted by gotswap

Mine was pulled with stock exhaust for months, no issues. It is free and quick and easily reversible, those connectors are kind of a pain to get at.

I concur. fuse pulled on 2017 for years with no issues, automatic trans.

almost 5 months on current 2018 zl1 with fuse pulled, also automatic, no issues.

This is actually the first I've heard of someone having cel's with a npp fuse pull, ever.

[JasonSB]

No need to pull the fuse. Just go to infotainment and set the exhaust to track. It will keep them open all the time.

[crosive]

Originally Posted by JasonSB

No need to pull the fuse. Just go to infotainment and set the exhaust to track. It will keep them open all the time.

No it won't. It will still partially close while cruising.

[JasonSB]

Originally Posted by crosive

No it won't. It will still partially close while cruising.

I havent noticed that. Same sound for me with the fuse pulled. Although I have headers and its loud any way

[crosive]

Originally Posted by JasonSB

I havent noticed that. Same sound for me with the fuse pulled. Although I have headers and its loud any way

There is a difference. If you rig up a switch to remotely "pull the fuse", you'll notice the difference. Especially if it's once the muffler gets some heat into it.

[gotswap]

It closes at part throttle and cruising. Very noticeable once you get an aftermarket exhaust. Fuse pull keeps it open all the time.

[Vigilante375]

I pulled out the fuse for about a month and noticed my blind spot thing in the mirror didn't work. I put three fuse back in and it still doesn't work.

Honestly im glad it's not there anymore.....

[Flytetymex]

Sorry for the rookie question. Based on OP's post, keeping the valves open will produce more crackles and gurgles. Is this true? I love this car but the one thing I miss is the constant gurgling I used to get from my Chevy SS even with regular neighborhood driving.