True - False?

[Anonymous]

hi guys, i was speaking to someone about the removing of the pre-cats (a Mr T Mechanic) and he told me if i remove the pre-cats apparantly id then need to replace them with something?a performace part maybe out of max power or something?  is this right?

[Anonymous]

Nope, the pre-cats just sit inside of the manifold. When you've removed them (i.e. smash them to bits) you just replace the (now empty) manifold.  If you were to remove the manifold completely then obviously you would have to replace it with something else, and ineed there is a performance part available, but it's very expensive.

[Anonymous]

he must have thought that i wanted to remove the manifold then, rather than remove the cats and repalce manifold, cheers bud

[Tem]

Reddi, rear GSB's excellent writeup about this, which I just upped.

[Anonymous]

cheers, now i just need to find someone to do it   s:o s:o (

[mrsmr2]

Sometimes the back pressure is needed for the engine management to operate correctly.  If the cats are removed, something else has to be put in place to put back the pressure.  He may have been thinking of this.

However, I think is more related to the main cats and not the pre-cats.

[Anonymous]

I think he was probably getting confused between the main cat and not the precats.

On another topic:

  s:?: :?: s:?:  Does removing the precats increase the load on your main cat and cause premature damage to it  s:?: :?: s:?:   (obviously the risk of everything failing will damage the main cat more if you haven't removed precats)

[Tem]

Does removing the precats increase the load on your main cat and cause premature damage to it  s:?: :?: s:?:

I'm not an expert on cats, but I believe they just do their job, no matter what the input is. If you give the cat cleaner gas, it will also come out cleaner. If you give it more pollution, the output will also have more of it. It won't work harder to achieve the same result.

[Anonymous]

do you think that a normal car mechanic at a local garage would be able to remove the pre-cats easy enough? ive got a friend who works in local garage but wasnt sure about asking him

[kanujunkie]

should be able to, not a big job, 12 bolts, 2 gaskets and a hammer drill, no worries

[Anonymous]

and would they have a hammer drill there?

if so then i guess id just need to print the removing instructions and leave him to it.  Any idea where they are again as i cant remember?

[kanujunkie]

fair point on the hammer drill, the pre cats are located behind the heatshield that you see as you look at the engine block

[kanujunkie]

behind this heatshield

[Anonymous]

s:?: :?: s:?:  Does removing the precats increase the load on your main cat and cause premature damage to it  s:?: :?: s:?:   (obviously the risk of everything failing will damage the main cat more if you haven't removed precats)

I'm fairly sure not (as Tem says).  However, even if there was a slight risk of this occurring, it's still preferable to your engine blowing up...

and would they have a hammer drill there?

You don't need one - I used a hammer and a large screwdriver (as in GSB's original 'how to' article) as I wasn't sure about drilling into it (not wanting to go too far and hit the side of the manifold).

[Anonymous]

you got the link for the how to?i cant find it?

[dimwit]

 m http://www.mr2roc.org/phpBB2/viewtopic.php?t=3507 m