Any help appreciated. My 2002 1.6 Vauxhall has an annoying intermittent problem. Sometimes it hiccups at about 3000 rpm, a spanner symbol lights on the dash and it won't rev above 3000 but keeps going quite happily below this. This is the get-you-home limiter. So, what is it. My thoughts are knock sensor or ECU. Any other thoughts?
Thanks
Martin

crank or cam sensor would be my first thought, although EGR valves are quite troublesome but don't generally reduce engine revs.

or lambda sensor

Thanks for the replies, Looks like I may need it to be diagnosed by machine. EGR valve is at least cleanable up so I may try that first.
Regards
Martin