Quote:
Originally Posted by Rincewind
I need to check this but I think that a cat is required for the MOT as they have been strapped to cars since 1991 and are now mandatory. I could be wrong but reading the stuff that I do a cat must be in place.
I shall confirm (and besides de-catting doesn't really do much for the emission in fact it throws things to the wall with regards emissions limits, CO and CO2 limits as well as the OBD requirements and if the system is worth its salt the MIL will activate as the OBD system is triggered) all of this information but I personally feel that taking a cat off a car is not a clever thing to do.
I know that the strangle the engines performance (they are even worse with a DPF - Diesel Particlate Filter) but they are there for a reason.
I shall check! It's a long and on going debate!
Nic
|
The MIL may well illuminate on the lambda sensor equipped models (2006 onwards I think) so a decat may not be possible on these. Otherwise there is no way the ecu knows whether the cat s there or not as there are no sensors in the exhausts system.
I believe the main reason for cats on diesels is to simply to reduce the exhaust pong, which is as good a reason as any.
I hate the smell, however I'm fortunate enough to live in a very rural & largely traffic free area so won't be offending anyone. I might even help keep the roads clear of the millions of suicidal game birds!
Lets face it any mod you do to the engine may affect the emmissions so it is down to personal choice as to how far you go.
If the tuning industry was proven to be a major contributor to increased vehicle emissions, you can be sure it would have been regulated out of existence by now.
Enjoy your driving while you can...
A couple of other points came to mind whilst I was out with the dogs:
From an emissions point of view, a rough and ready guide is the fuel consumption. If any mods worsen this, then the emissions (CO2, HC) would be worse. The decat could actually improve the CO2 emissions if mpg improves, (which is possible, we'll have to see..) at the expense of HC. My tuning aims are to enable the untuned fuel consumption to be achieved when driven in the same manner and this has been the case with both of my 45s and the 75.
The dreaded maf sensor. This single component must be far more responsible for worse emissions than any tuning. Depending upon the way it is failing, fuel consumption can increase significantly resulting in more CO2 and HC.
No wonder lambda sensors have been introduced!
Ron