Cat removal

[Jez1516]

Hi all Removed my Cat and since i removed it, it seems to smoke when it starts and after i sit for a while then move any ideas much appreciated.

[Coonper]

Nothing to do with the cat mate.

Did you use any sort of oil on the exhaust bolts? If so then thats what it will be.

Or it could be the paint on the decat pipe.

[Jez1516]

No no oil on the de cat pipe. Could it be the piston rings or something technical like that

[Coonper]

No no oil on the de cat pipe. Could it be the piston rings or something technical like that

If its only when you first start it up then i expect its just steam.

I would only worry if the smoke is coloured. If its just white smoke then dont worry about it.

[Quick]

Could be valve stem seals going!
How many miles is the car on?

[le_petit_gaulois]

From what I've heard u wont notice any gains by removing the cat. U could just buy a racing one. :)

[Coonper]

From what I've heard u wont notice any gains by removing the cat. U could just buy a racing one. :)

Not sure who told you that...

Why spend £200 on a sports cat when you just decat it (which is better) for £30.

[Mini-valver]

Check the colour of the smoke. Excessive white can mean HG but it would be all the time to be fair, blue will be oil so either rings or stem seals. If it's just vapour, it could be unburnt fuel so check your plugs for colour, they should be like brown sugar or slightly sooty. Wet black is oil or excessive fuel, or matt black is a rich mixture.

[Jez1516]

It's a blue colour and my car has done 100,000 thou miles

[saunders]

I dont think they understand where your coming from with this problem. I had the same thing when I had a piper 4-1 fitted. Basically I would turn the engine off and as I walked away it would smoke like a left cigar. I was told it could be due to the manifold bedding in but it was only on for a week or so. But my car was fine I just decided I didn't want it anymore. So I wouldn't really worry, unless its lots. But mine was only marginal plus it was during the winter, but I guess because there is nothing restricting gas flow anymore, any fumes still in the exhaust after its turned off can now excape:y:

[Jez1516]

Nice one m8.:y:

[saunders]

Nice one m8.:y:

Yeah I honestly wouldn't worry unless it is a huge amount of smoke. Plus if it wasn't doing it before then it is just as I have explained above:y:

[Quick]

As its blue, is on 100k and does it on start up & after sitting a while I still go by my first guess - Valve stem seals!

Does the car use much oil?

[Jez1516]

Yh it does it uses quite alot.:panic:

[KamRacing]

if its using oil and its not leaking out the engine block then you are burning it..

compression and leak down test can help diagnose the problem

[bullit]

I dont think they understand where your coming from with this problem. I had the same thing when I had a piper 4-1 fitted. Basically I would turn the engine off and as I walked away it would smoke like a left cigar. I was told it could be due to the manifold bedding in but it was only on for a week or so. But my car was fine I just decided I didn't want it anymore. So I wouldn't really worry, unless its lots. But mine was only marginal plus it was during the winter, but I guess because there is nothing restricting gas flow anymore, any fumes still in the exhaust after its turned off can now excape:y:

what he said