1.3 Lanos misfire/flat spot

[mutchy7]

Hi people new to this forum i have a daewoo lanos 1.3 1999 which is giving me a bit of bother just now with an intermittent misfire/flat spot
sometimes it runs fine and then other times has a flat spot/delayed reaction when accelarating after junctions and slowing down etc and sometimes it will just misfire when driving along the road
any ideas what could be causing this?

the spark plugs are reasonably new and i replaced the the HT leads about a month ago as one had broken in half so shouldnt be anything in that area
thanks for any help in advance

[Daniel]

Hi,
Was check engine light ON?

Start by checking:
-Fuel filter.
-Fuel pump.
-Ignition coil.
-EGR valve if equipped.
-Sticky valve(s) / lifter(s).
-Trottle position sensor.
-...

[Rodd1s]

I've had similar symptoms on my previous 2002 1.3 Lanos and it turned out to be a worn out lambda (oxygen) sensor.
Located on the exhaust manifold near the head, with either one or two wires leading to it.

They are exactly the same as on all similar age Vauxhall/Opel/Holden small 4-cylinder engine'd cars - and are typical of dying after some years.
I eventually replaced mine with a sensor from a Vectra B (as it was a cheaper option, somehow) and it was fine again.