Hi all

My v4 sti has always idled a bit rich, at around 12.5 - 13. its great on cruse and on boost, getting close to 14.7 and 11s. tonight i was parking up and the afr was bouncing around 11 - 12. i pressed the brake peddle and it jumped up to 13 and settled back down to 11.5 ish. i pressed the brake peddle again and the afr went as high as 16 with continuous light pumping. then back down to 11.5. Its a wideband afr, an innovate mtx-l. Why would the brake peddle alter the afr/fueling. i can hear the engine note change slightly.

any ideas?

Cheers

Rich

 

Has it always changed when push brake my friends innovate also shows different readings when push brake

 

only really noticed it today.. been looking into it and seems that its the servo revacuuuming itself... i dunno tho... some times its hunts on idle and pressing and releasing the brake stops it. wierd