blinkin eck

[l455lnk]

advice please gentlemen
94 aby s2
109000 miles
heavy misfire under hard acceleration
blink code 2121
i think the code descriptions can be very woolly and misleading. I recently had another code which directed me in completely the wrong direction, indicating a cam position sensor, and it was thanks to mr murray pointing me in the right direction that the air mass flow meter was replaced and all was well.
what would you look at first?
cheers
paul

[denniselbows]

if the 2121 blink code is the same as on the 3b then it is the idle switch in the throttle position sensor make sure it clicks when the throttle is closed if the blink codes are different on the aby then forget the above

[Tonks4x4]

Do a quick boost leak test aswell to rule out that as a possible cause.