would a lamda sensor stop a astra gsi mk3 from starting

[A18N]

my astra mk3 gsi has not started for the last week so i had a look, the engine management light doesn't come on any more it used to come on for a second or two when started so trying to get it started i took the first spark plug out to see if there is a spark then turned the engine over and there was a spark it try'd to start so i stoped and put the bits back together and trty'd it again and it fired up so i ran the diagnostics and the code read out error 173 this is a HEGO sensor (lamda sensor) is this the reason why it hasn't started for the last week please please please help my head is done in trying to get it sorted

[chas2008]

unlikely a hego sensor would stop it starting, run rough but not prevent starting.
Diagnostic codes are not always right, this one in particular usually turns out to be the airflow sensor many a lamba sensor has been changed for no reason.

[A18N]

so does any one have an idea what would cause the car not to start or cause the engine management light not to come on for the first few seconds while starting thank you for any ideas!!!!