change from cat to standard exhaust? anyone tried this...

[marc69]

My 1.2i keeps rubbing the cat as it treies to go on my drive (peak at pavement). I have tried raising the exhaust etc but to no avail. I do not want to raise the car as I quite like the lower suspension. I noticed my standard 1.2 exhaust is far higher on the car so am going to try to swap to see if it clears

i assume the swap is easy as the manifold looks the same (except it had a sensor in it) and the exhaust brackets are on the car?

[phunkynova]

I've not tried it but what about MOT time ?

[Mazz]

It will need a CAT for the MOT, otherwise the emissions will be out and fail :(

What year is you car?

[craig green]

Just keep scraping it............. obvious answer.

[AlexW]

You would need to change the front section that connects to the manifold right back to the backbox (But not the backbox itself of course), this is due to the Cat/middle section flanges rather than the slot fit 1.2 carb stuff.

[marc69]

Thanks, for questions, I was going to just change it again for MOT.....oops. I can't keep scraping it as it is pretty harsh scraping and I am more worried that I will permantly damage it. I bought the front and middle section today, was about to remove it and guess what........the bloody back box will not seperate from the middle , after 1 hour i gave up, put it ll back on, will eave it again for another day when I have more patience left.

[paul james]

I've done this on my old 1.2I, and like others said, it failed on MOT emssions test - or at least should have done had the garage I frequented at the time not been dodgy and passed it anyway.

[marc69]

I assume the car went fine otherwise but did it go any faster!!!!!!

[paul james]

It went fine yeah, but didn't really make much difference (if any really) to performance. I've read before that the CAT was the main reason for the 10BHP difference between carb and injection 1.2 novas, but I don't think thats true at all. Its a cheap mod to do, but a hassle come MOT time.

[marc69]

well so long as rear bolts come off ok, I won't even seperate the front, middle, just the 2 spring scew at manifold and two for rear pipe but as I had said, I am stuck as the back box will not move.

[GDN16v]

Just weld a rally-esque skid plate on the bottom of it to protect it!;)lol

[marc69]

haha! If you want to do any wleding, I have plenty of welding on old cars for you to do!!!!!

Regarding the 10 bhp between earlier and injection models, I thought it was mainly due to the small port in the heads to help with emissions?

[brainsnova]

the backbox will come off if you open the join up a bit where the slot is and hit the join with a hammer then try and move the back box up and down and turn it etc once you see it move your laughing.

[Sturge]

As said already, easily changed. I changed my SRi to a non cat gsi exhaust by changing the downpipe and centre section. With that and an induction kit it was rr'd at 92bhp at the wheels, up from 80 beforehand with just the induction kit.

Also, i didn't have a problem getting through the mot as although it technically shouldn't have passed because it didnt have a cat, unless you're on an L plate, as long as you pass the emissions (which weren't adjusted for the cat versions) then you're fine

[marc69]

Thanks, will try seperating the rear and middle pipe, if the emmissions is OK until Lreg, I may leave the ordinary exhaust on and only if he fails the car, then put the cat exhaust back on, but I think MOT testers are usually quite reasonable to see a Nova still on the road. There are pretty rare up here.

[marc69]

changed the exhaust today and actually managed to get the car on drive with only the front mudflaps scraping so real progress there. There must be a few inches of difference between the two exhaust types as it had loads of clearance compared to the middle pipe and cat being pushed up..
I still couldn't get the back box off, so......i smashed the pipewhere it goes into the box to allow me to remove it. Even after removal, the end bit is so corroded inside it looks as though it is welded!
Anyway, I am very pleased and although the car is defintley no rocket, you can tell that it is breathing easier ( I did put a KandN filter on too...nice induction niose).
Anyway, thansk to everyone for opinions and advice.