Pre Cat Removal

Mark_Dj

I did this mod to my Sri and she feels a little better now. I have seen on other forums you could gain about 6 or more bhp from this mod. My exhaust system sounds different also from this mod, better 😃

Pre Cat:

Pre Cat Removed:

phil-h

Bewen thinking bout this mod for a while now, how difficult is it? Looks too much of a job for me tbh, on-road parking, every chav walks past wants to know what im doing lol 🙂 Might be able to get it to a m8s for a few hours, but concerned about shearing bolts while trying to drop the pipe 🙁

Mark_Dj

The bolts are easy mate, they are not rusty like some cars as they are more hidden away from the bad weather 🙂. The part that comes off from the cat pipe to the engine is held on by 3 nuts, then just your normal exhaust clamp to remove. You will also need to screw out the 2 exhaust sensors on the exhaust pipe. Easy enough 🙂

Kidd_Sri

anychance of a photograph on where it is,and wot to do? going to have my car live mapped on tues so wanna do this before the day for better gains 😃

Mark_Dj

Kidd Sri said:
anychance of a photograph on where it is,and wot to do? going to have my car live mapped on tues so wanna do this before the day for better gains 😃

Pictures now above in the first post ^. You can see how much the air flow is blocked.

Kidd_Sri

i can only see this, its that where it should be at ? im assuming its little difficult to get to?

Mark_Dj

Thats the part where you remove the heat shield using a 10mm spanner and remove the 3 bolts. You will then see the exhaust manifold and that has 3 nuts to be removed. You will have to remove these from under the car, using a socket and extension bar and rachet. Then remove the exhaust clamp joining to the cat and the exhaust manifold.

Kidd_Sri

thanks sounds abit fiddley getting under the car, guess im gonna have to jack it up or something. Is it best to remap it straight after or is it ok for a week or so without doing anything? ive booked it in for tues but after seeing this makes me wanna scratch my head and hmm for a while lol

Mark_Dj

I have no longer got my re map and I am running this as it is. It's fine without the map or re map it and feel the difference rallygif . Once you re map your car it should feel better anyway. I removed my pre cat by using the normal car jack and slid under it. It's best to leave the bonnet up to let the light shine through :wink:

phil-h

That is some major restriction, ffs. Ok, now i see how much there is blocking the exhaust, want to get this out of my motor asap. Think I'll be booking the m8s driveway next week 😃

Mark_Dj

Nice to hear you will be doing this mod phil, let us know how you get on :wink:

pg325

Will this be the same on all ages cars, mines a 53 plates, was thinking of doing this, but somebody told me on newer cars the baffle wasn't there?

Mark_Dj

Ffoeg may be able to help on that one. I would think it was the same as all the others but you never know notsure.gif

Ffoeg

The pre-cat is one of the things that makes the 2.2 Euro4 compliant, so it has to be there at manufacture, and all 2.2's should have them.

However I did hear that VX had a job getting them for a short spoce of time,and so a few cars were fitted without them.

Only way to check tho is take a look (or a feel) - drop the front pipe off from the manifold, and stick you finger in the gap, and see if it's there or not.

vocky

the later engines (2.2 direct) have their main cat next to the manifold

Ffoeg

vocky said:
the later engines (2.2 direct) have their main cat next to the manifold

That would be the Z22YH tho :wink:

Daz

Done this mod after work today....Taking the downpipe of is easy,,,,but getting the precat out.."Nightmare" Drilled it,,chiseled it,tried burning it out ,,,,All failed....in the end i cut the down pipe off just below the precat and using a large socket and larger hammer i beat it out....then welded the pipe bk up.....car feels more responsive but it cud just be me...Also fitted my magnex rear box and cat back section...

Gazza

thats extrme isnt it notsure.gif

going to have a go at mine sat hopefully i wont have to much trouble notsure.gif

Mark_Dj

Good job done then in the end 🙂 . Mine was also tricky to get out :? . Did you find it hard getting the down pipe and cat separated from the rest of the exhaust?

Gazza

what do these oxygen sensors look like notsure.gif

thats the only bit im not sure of