Emissions help needed with mark 3 golf

[mrtat2k9]

The problem is the emissions are far too high for the mot.

I’ve changed the plugs, leads, cap rotary arm and coil,

Also changed lambda, temp sensor and single point injection unit

It’s very rough on idea also it sounds very load at the exhaust end when its idling

Does anyone have any ideas?

[Tony Stark]

Is the exhaust blowing at all? Even a small blow in the exhaust system can cause problems with emissions on a car with a cat.

Is it a standard exhaust thats on the car?

Just double check that the injection unit/throttle body mounting gasket is ok and all vacuum pipes etc not leaking letting air in.

Is the engine and cat hot enough when its being tested? Might be worth giving it a real good hammering round the block to get it proper hot.

What exactly is failing on the emissions test?

[mrtat2k9]

thanks for the replay
Its not blowing and it is only a standad exhust on the car.
forgot to say about the cat its geting very hot.
iv tryed new gaskets on the manifold.

[fourringsrus]

If your emissions are high and your exhaust is sounding loud, maybe the guts of your cat has been spat out in time.
I have had similar issues with a v6 ABC Audi coupe and it was cured by changing the cat.That is assuming you have a cat

[mrtat2k9]

it does have a cat and i did think that cat was at folt but it still runs ruff with the cat disconcted