156 1.8 T Spark - Catalytic Converter Issue
Looking for some advice on the best/cheap (yes I know these rarely go hand in hand but looking for a compromise!) fix for the issue my 156 is going through and figured that its a safe bet someone might have been through a similar issue!
Had the car for 4 years now and absolutely love it and experienced very few issues, keeping it regularly serviced and generally looked after (dads had a few Alfas, a 145 and a 3L 166 so know they need some TLC). About a month ago on the motorway after a few hours of driving the temperature spiked suddenly and power dropped off, would just about do 60mph but when I put my foot down there was just alot of induction roar and no power. Pulled in and waited for it to cool off and started off again, car was down on power but could just about manage a steady 65 on the flat - driveable but far from ideal.
Took it into a local garage, an alfa specialist in the south west, who changed the Lambda sensor on one of the front cats (fault thrown up by the diag kit). Drove alright for a while longer, next motorway trip resulted in the same issue after about an hour or so. Variator was the next best guess with a rattle coming from the engine at idle so as the cam belt was due got that done at the same time, wallet didn't enjoy that!
Seemed to fix the issue but again after a bit more motorway driving same issue, temp spike and down on power. Eventually narrowed it down to one of the front cats and the rear car disintegrating and blocking up the exhaust causing the Lambda failure and temp issue.
Nearly £700 down in the last few months on this fault already so replacing 2 cats with stock components is out of my budget currently, at least for a few pay days! As I can see it I can either put cheaper aftermarket cats on (not a clue on brands etc), take them out completely and decat (lots more noise - I'm not 18 any more!) and put the original cats back on for the MOT or keep driving it as it is for 2 months until I can replace with legitimate parts (not sure if this will do any lasting damage, only short commuting and one longer trip).
Any help or suggestions would be much appreciated!