Engine management light?!

[Danherring]

Hi guys & girls, i recently changed a exhaust manifold and down pipe on my car and it didnt work so i changed it back to the standard one with the 'cat' on. but ever since my engine management light has stayed on... any ideas what this could be?

help much appreciated.

dan.

[Bensvts]

did you unplug the oxygen sensor, or put a decat in, then start it?? why didnt the other manifold + downpipe work, did they just not fit??

[deks36]

it means you have a fault it needs to go on a code reader to see what fault is and be cleared most probably as you have interefered with the exhaust system its upset the lambda probe reset may sort it

[Danherring]

i have a MK2 VTR. it had a magnum supersprint backbox, supersprint straight threw centre pipe. then a cat on the downpipe then a manifold.

i tried to replace the manifold that had the cat on it with a manifold that had no cat. ( come off a mk1 saxo) but the lamba sensor whole was in the wrong place and couldnt fit the lamba sensor in the whole. so when i started it up it had air coming straight out of the manifold as there was a whole an no lamba sensor.
i then put the original manifold with the cat back on, screwed in the lamba sensors started it up and engine management light has stayed on since...? :ouch:

[Bensvts]

it has brang up a oxygen sensor fault then as you started it without it plugged in you will have to go to local garage to get it plugged in and erased then will be fine :y: