edward

I was talking to a chap who makes exhaust, only briefly mind you and was talking about a GTA exhaust. I tried to explain the cat set up on a GTA in the following terms. I explained that from memory it has two precats on the manifold section and two cats under the central section of the car.

His thought was that when the car was running hot there would be sufficient catilisation within the precats for the MOT and it would be possible to run a straight through pipe instead of the cats under the car. He indicated that if at the MOT station the car was cold there would be more of a problem and that to a large degree is why you may have 2 sets of cats. Basically to improve emissions from a cold engine. Oddly in the past, on my wife's diesel Range Rover I took it to the garage and it failed on emissions. The MOT station was just down the road. He said take it down the road and give it a good long thrashing. (bit difficult in a 2 tonne 2.5l diesel - but still). Brought it back and it sailed straight through the emissions test. He was saying that it is much easier to pass emissions tests through catalysers with really hot exhaust gasses.

So, going back to exhaust building man - he agreed and said that would be the case with using either set of cats on the GTA, but when going for an MOT make sure that the whole car was nice and hot when tested. He said this would all be legal and cosha!

The only question I forgot to ask, in the couple of minutes I had talking to him is what to do with the sensor. I can't remember if there is one or two on a GTA but if you remove say the cat under the floor of the car, do you have to move the sensor and insert it into a certain part of the exhaust. That is not difficult to do, I would just need to know where.

Please bear in mind all of the above was all opinion, not necessarily fact, we were chatting in a car park - so all always, a pinch of salt must be thrown into the mix!

E.

Edward