Need todo the
clutch, engine out
Join Date: Nov 2013
Location: United Kingdom
Alfa 156 2.5 v6 failing mot on emissions
Any advice would be very much appreciated.
MOT time for my 156, had a load of work to do such as brake pipe, cv boots, front discs, bit of rust etc... Got all that done, then failed on emissions, details below details below for second fast idle:
CO limit 0.2 actual 0.18 pass
HC limit 200 actual 418 fail
Lambda limit 1.030 actual 1.211 fail
At this point they said it was the lambda sensor
Replaced it them went back, details below for second fast idle:
CO limit 0.3 actual 0.57 fail
HC limit 200 actual 50 pass
Lambda limit 1.030 actual 1.026 pass
At this point they said there were holes in the front pipe which gases were escaping from, got it replaced, also found a spilt in the crank case breather that goes from one side of the engine to the other, wrapped gaffa tape around it to tide it over until I could find a new one.
Went back results are below second fast idle:
CO limit 0.3 actual 0.63 fail
HC limit 200 actual 44 pass
Lambda limit 1.030 actual 17 pass
I have done a bit of reading and am now thinking:
Air filter needs replacing
MAF needs replacing
Catalytic converter needs replacing
I have looked at the air filter which has been on the car for less than a year and it looks OK, I will replace it anyway, but apart from the cat I am not seeing anymore that can be done.
The cat is not the original so it could be that, I will get it off the car and give it a shake and look inside it the best I can as I have read they can get blocked or any vibration inside them could indicate they are failing. I have run the engine at idle, then disconnected the maf, the engine revs drop quite a bit, then the engine recovers. Revving the engine with the maf disconnected give very lumpy running, then connecting again and the engine revs and idles fine. I have a 147 as well so I could swap the mafs and see how each engine runs then, but I suspect they will be OK anyway.
So with that I can only see the cat may be in doubt. Apart from that, I can't see a future for it.
Any advice you can give would be good, thanks again.