Has anyone ever had an issue with the exhaust valve only partially opening in sports / race mode in the Mk8 Fiesta ST (I have a pre-Sep'2020 model)? I've just had a new Milltek exhaust system fitted but i've noticed the valve only turns about 30-40 degrees when I put the car in sports or race mode. I've had someone rev it a bit for me in sports mode whilst I look at the exhaust, but the valve still doesn't fully open. I'm running the mountune m235 software and thought maybe it would be programmed to only partially open the valve at idle to keep some back pressure in the system but I'm fairly certain this isn't the case. I've emailed mountune to ask. Is there a way to recalibrate the valve position? I'm not getting any fault codes on the OBD reader.

 

Appreciate any help on this.

 

 

This is a bit like the question we've raised before on what exactly does Sport mode do and no-one seems to know for sure!😀

I've had a look at mine (standard exhaust) when idling in both normal and sport modes and it didn't seem to open much even when revved. I don't know, but suspect that it may be mapped to only occur at certain revs under load.

There's been a lot of discussion on this on the ST specific forums**, but I've not seen a definitIve  answer. 

Edit: **some interesting comment on this thread:

https://www.fiestastoc.com/threads/exhaust-valve-control-mod.325660/

Also, no doubt you've seen this (or similar) but looks like post Sept 2020 only:

https://milltekexhaustshop.com/products/milltek-ford-puma-st-1-5-ecoboost-opf-gpf-equipped-2020-2023-active-valve-control-exhaust?pr_prod_strat=e5_desc&pr_rec_id=55089ebcf&pr_rec_pid=14879843156353&pr_ref_pid=14879843385729&pr_seq=uniform

Interesting, I didn't realise the valve opened and closed dynamically in sport and track mode. I also don't know how the M235 software differs to the standard Ford engine mapping in terms of valve behaviour but I'm pretty sure it's not meant to be partially open at any point. It's definitely meant to stay fully open at idle when in sports mode. See the video attached at around the 11 minute mark. I remember looking at the valve on my stock exhaust year ago and it did the same, it would stay completely open in sport or track mode at idle. I've got the car booked into a garage on Friday for them to look at it.