would a failing amp sensor cause a miss at around 2800rpm in sixth gear. At no other point when driving this issue occurs just at this speed and gear.

Car is an 2005 Impreza sti uk

 

Standard or mapped?
Is the misfire on WOT or cruise?
Could be one of a few sensors or a leaking vac/boost/exhaust pipe.
If it's only happening on full load and WOT in 6th then could be a boost spike?

 

Mapped, happens when car is on cruise once the car comes on boost and full load the car is fine

 

Depending on what ECU/software you're running then I believe you can have 'Map per gear calibration'
Has it always done this since the remap?
Have you tried an ECU reset to see if this sorts the problem?

 

Standard ECU not sure on software. Only started last week or so ago, excuse the dumbness but how do you carry out the reset is it just disconnecting battery for a period of time?

 

Not 100% sure on a newage but I've heard people disconnecting the battery,pumping the brakes and leaving it 30 mins will do it? I'm not convinced this would do it properly but I've never owned a newage so?? Maybe worth having a search.
I know it can be done properly using a simple/cheap obd fault reader or vag com cable with software like romraider or ecuedit.

 

yup - 5.99 fault reader off amazon or a 5.99 vagcom cable and fressm/romraider software on the PC should be able to issue an ECU reset. However if it's only just started happening then I'd be leaning towards sensor dying or small vac leak somewhere. At high gear/low speed the load will be a little higher so if your leaking in some air (or leaking out some exhaust before the o2 sensor) the ECU's fuel correction will swing the wrong way and can lead to a miss.

best to see if there's a local garage who can do a quick diagnostic to see if anything looks suspect, might save you a bit of time in the long run.

 

Thanks for the advice guys