330i SE NOx/CAT problems

[Luke330i]

Hi all 

 

I'm having issues with my car giving catalyctic converter efficiency faults. The car has been into a BMW specialist and they have advised the Cat needs to be replaced (apparently they have used an endoscope to confirm the CAT is knackered). Luckily for me its under some form of warranty from the garage I got it from but they dont want to go with the stock replacement from BMW £1800 in the hole.

 

The solution they have offered is a custom fabricated powerflow exhaust from the pre cat to the back box.

 

From what I have been reading will this sort the issue? Does the NOx sensor need replacing as well? Is it worth taking out the underfloor cats and mapping the NOx out?

 

Any advice much appreciated

 

Luke 

[Greydog]

Morning Luke

I may be wrong but if there is no Cat present it may fall foul of MOT rules even if the emissions don't. Why can't they just change the Cat??

My sons Toyota pickup needed a new cat the garage he uses fitted a 200 cell after market cat reset everything and all good, that was about 3 years ago.from memory the whole cost was about £200

Mind you if they are offering a full stainless powerflow system !! Just make sure it is fully compliant so you don't get caught out, talk to an MOT station or check MOT regs on line.

Dave

[Luke330i]

Hi Greydog

The reason for not doing the bmw replacement is the 2k cost. They have agreed to the powerflow.

So they are installing a powerflow from the 2 precats on the manifold back...it had a powerflow box on it last year and that is still in good nick. From what I can work out the powerflow should do the trick but I dont want to have issues with the NOx after this is installed. I am guessing if the NOx is seeing a decent flow from the CAT it wont have any problems (current one is blocked apparently)

[Greydog]

Stainless over mild steel even if it is OEM winner winner 

Dave