Fuse 15 Query

[Jedster]

Sorry for reviving tis thread, but I cant quite find a definitive answer for my query with regards to pulling Fuse 15.

As a happy owner of a one month old P450 I happily pulled Fuse 15 and instantly noticed the change in exhaust note at lower revs with more popping, crackling and all the stuff that makes us smile .

However I have recently been told keeping your exhaust valves open all the time could affect engine management or damage the valves. I'm intending to keep my P450 long term so was wondering whether I should plug Fuse 15 back in just to be safe

Can anyone give a definitive answer as to what long term affect keeping the exhaust valves open all the time could have?

Thanks in advance

[mickjaguar]

I can't see how having the exhaust open would damage valves or the ECU. The dynamic setting and exhaust button in the early cars just opened/closed the exhaust on demand. I used to drive around, in my 2015 car, with the exhaust open the majority of the time, as most owners probably do. The feature was changed from 2018 to meet stricter noise regulations, so that the valves just don't open as early or on demand now.

In theory the problem could be that the values might sieze in the open position, through lack of movement. Although, these the later cars have valves with improved flap bushings which aren't as prone to siezing up like the early ones. I haven't heard of anyone that's had a Fuse 15 problem over the last 3+ years since I've had one of these models (in the UK or US). What you don't want to be doing is inserting and removing it too often, as the fuse box isn't really designed for that. Rumour has it that someone forgot to put it back when their car went in for warranty work, but the technician just wanted to know what had been done to the exhaust to make it sound better .

[WShudds]

Just to add to the above bear in mind that an error code will be stored on the ECU when removing the fuse. Putting the fuse back and clearing the code might be wise if you ever have to sell the car.

[YorkshireSam]

Sorry for reviving tis thread, but I cant quite find a definitive answer for my query with regards to pulling Fuse 15.

As a happy owner of a one month old P450 I happily pulled Fuse 15 and instantly noticed the change in exhaust note at lower revs with more popping, crackling and all the stuff that makes us smile .

However I have recently been told keeping your exhaust valves open all the time could affect engine management or damage the valves. I'm intending to keep my P450 long term so was wondering whether I should plug Fuse 15 back in just to be safe

Can anyone give a definitive answer as to what long term affect keeping the exhaust valves open all the time could have?

Thanks in advance

I've run mine without 15 in the past. It does sound awsome. It's currently back in after I had to replace a faulty exhaust O2 sensor.

Yes, F-Type O2 sensors tend to be a bit fragile. However, it did get me wondering whether the extra pops, crackles and changes in exhaust flow after removing fuse 15 could lead to O2 sensors sooting up/ malfunctioning.

I believe 'pop & bang' remaps which are popular on some cars now can put extra strain on exhaust sensors and cat systems, leading to premature wear.

I'd be interested to hear any other views on this.

[WShudds]

One of my downstream O2 sensors failed with 29K miles and 3 months after buying the car. Not a big deal and it got covered by the RAC warranty. Shortly after I decided to remove F15 and it's been running absolutely fine. The extra noise is worth it IMO.

I wonder whether the unrestricted exhaust might have an overall positive effect on parts and performance.

[cj10jeeper]

I’d the question into two parts.

Whether the bypass valves are opened or closed doesn’t make any difference to the pops and bangs, other than making them more audible, so on that part I’d say. Big benefit to those who like the noise at all times and perhaps very minor benefit of being a slightly less restricted system.

However, pops and bangs are a result of fuel being fired on the exhaust stroke either by retardation, plug firing or fuelling, typically controlled by a part of the ecu map. That can be an issue. Viezu make reference to it ‘cremating the exhaust valves’. I also cannot see how you can in effect run endless explosions in the exhaust system without it having a negative effect on the components in and part of the exhaust, be it temperature, shock, etc.
How much is somewhat unknown, but we can assume JLR thought it acceptable within the standard maps of the ecu and system, but likely didn’t plan for removal of a fuse, or. Driving in a manner to induce them continually.
I therefore use the feature of pops and bangs, but not to excess.

[Jedster]

Great answers all! Its great to hear some differing opinions on this. The only downside being is that one moment I'm thinking of popping it back in and one moment I'm thinking I will definitely keep it out.

Pops, bangs and crackles aside, I'm loving the F-Type, its a fantastic car to drive!

[DOC IW]

There is a fairly easy DIY mod to make fuse 15 switchable with a remote control rather than faffing under the bonnet to physically pull and replace the fuse. It allows the car to roar when wanted, but purr quietly when preferred at the press of a button.
It was first described by a member of the US F-Type forum, but has now been described here on our UK forum too.
Search “Fuse 15 remote control” on this forum.
It has come to be known as the “claws out” mod on the US forum.
I have done this for mine and it works really well.