Catalytic Converters - Genuine or Non-Genuine?

[deadpheasant]

Hey everyone,

If my catalyst had gone would I notice a significant reduction in power? I've only owned the car a little while and I'm sure there must be more power out of the 2 litre M50 unit than I'm experiencing.

Obviously if it has gone, I need to sort it out, but would you guys reccomend a BMW unit over say something from here:

http://www.cats4less.co.uk/product_details.php id=1637&pr_pc_id=22&pr_man_id=6&pr_mod_id=21&searc htype=simple&startpos=0&max=10

(man thas a huge link, sorry) or German, Swedish & French Car Parts (this is a UK company)?

Basically are third party units worth getting?

Cheers

Neil

[BillionPa]

well, first find out the condition of the CAT before deciding on replacing it by doing an exhaust gas analysis.

[Ross]

You can check for a restricted cat. with a vacuum gauge. Hook the gauge to manifold vac., bring the revs up to three grand or so and hold the revs steady while watching the gauge. A dropoff in vac. while holding steady revs indicates restricted exhaust, likely the cat.
Don't expect much from two liters dragging 3400# around.
To answer your question. The aftermarket issues are usually fit and lifespan rather than working or not.
If yours is bad then it means it has lasted 15 years before failure. If you need another 15 years of service from it then buy OEM.