lumpy idle help

[JaYpLaYalfa]

Hi all
Im new to the forums and to alfas i have a 156 18 ts 52 plate
all has been fine love the car but it had a bad rattle comeing from the front cat
As the car had just had an mot i thort i would be clever and have a look removed the lambda and found the the honey combe type material was loose and rattleing about like in a tin can. So i cut open the cat and remove (with a full mask on lol) welded it back up and the car was fine
Now after about 300 miles EM light came on and the car will not idle its very lumpy the car is running fine apart from that
when i dissconect the maf it make no differce still bad idle
i have done ecu reset from this forum still no luck
Now apart from a new cat and lambda's do you think it may be the maf

Sorry for bad english

[JaYpLaYalfa]

sorry just seen this is in the wrong place

[Ralf S.]

No. If you hacked the catalyst it's probably the lambda. They're quite fragile. The symptoms will be that the idle is uneven and the car keeps trying to stall.. then the revs will go up to 1500 rpm and then drop down again.

Lambda can be damaged if you weld too close to it.


Ralf S.

[JaYpLaYalfa]

I did remove the lambda while working on the cat and the idle is not up and down its a bit like a big single silinder tiking over slow blum blum blum blum if you get me lol but reacts to the gas fine and it is still fireing on all 4
the idle sometimes gos ok now and then and is very smooth untill the EM light come on about 10 secs into starting
Its booked in at italin race services in basildon on sat hope mark can help