Well, well, well ! After trying a sh!tload of parts to cure a stalling problem i find a faulty CAT. I think.

I'd tried all the sensors and even a second hand ECU set but nothing worked.

So i thought of taking out the Lambda sensor (leaving a hole in the exhaust ) It started and ticked over albeit sounding like an old Tractor.

Thing is the CAT was new last year with a 2 year warranty-though a copy not a genuine part for 50 odd quid off ebay. They say if i return it they will test and replace it if found faulty.

Ive just never known it before though of course i dont work on cars everday as a DIY mechanic.

It cant be anything else but the CAT because thats the only thing between the engine and blow out.

But it seems uncommon to me for for a CAT to block emmissions so bad that the car would only start and run for a few seconds then stall.

What do you think ?

Well i know that the yellow turbo cinq for sale in the classifieds once had the CAT fail on it causing erratic running issues. Also my dads old merc sl500 had an issue with the cat. I don't think its a particularly common fault no but it does happen.

On the merc (as i actually took that off myself) what had happened was the internals had degraded and all that was left of it was a small egg sized piece which would at times block the exhaust and thus cause bad running.

You could take the CAT off completely and try starting the car, if thats the problem it should run ok with it off, albeit really loud as it won't have an exhaust. If the CAT is the problem then its likely you should be able to hear the internals rattling inside when you shake it, if you can get it all out then you will essentially just have a de-cat which is fine. Car should pass emissions without anyway but will get you moving in the meantime even if you do need to replace it down the line.

I took the CAT off and it isn't the problem, i could see through it.

Its the baffle on the back section, ive got mucky lips trying to blow through it, its constipated

Its lasted quite a bit longer than the other exhausts ive fitted so i presume its full of carbon.

Fault pinpointed but it might have been a lot easier if somebody had had the same problem and passed it on to me to check.

Taking the Lambda out as a test in the first place and i would have cracked it straight away.