@pippin59
As above, you are not the first, by a long way. This question and other regulars pop up in an almost random way, mine started rattling in around 2014, knew what it was from reading on here and fixed it similarly. No problems since.
Simplest fix is a very large jubilee type clip around the body of the cat.
Not to my taste but.
I took the outer shell off, had to drill out 1 or2 spot welds and bolted it back together with st steel fixings. Also used a U type exhaust clamp where a weld had broken where two goes into one on the piping.

I would suggest getting a cheap stethoscope.  At least you'll be able to pin down a general area where it's coming from. There are just so many possibilities.

https://www.ebay.co.uk/itm/325907031884?itmmeta=01HYMXDW4RE9HZN3XCC0WDGGB1&hash=item4be192a74c:g:gr8AAOSwf8xlZxwI&itmprp=enc%3AAQAJAAAA4MLL11yJSRQ69rIujPm1DC6pvACYFVhUpuma1h0fiq9BZNOXil7MUAo9qHBZ7iI2ozYPdcisROasUVOERAtI91ECCHkZPO7Ut0qa1nUQv%2BrgbUY6pkHWDf4XBxPSAyKkgvEPeQ1NzdLrnJ%2Bxt5J2W%2BluQfqa6By9k9VTElXvkGCHXFVAVMm70OP474AU%2F1xXoC6R%2B2sRNIVkImSedFUErJikvzxYdhtaNidW9BaU%2FXpBDoCNwCAo5dkCiUeaJ4DdTPxTwkNoJer5jf1AO4sLqkpjwAXsBUEEjAEPcGyTX6wI%7Ctkp%3ABFBMyMK3nfVj

Exhaust heat shield on cat loose

Hi all i have a 2004 roadster with an engine rattle at 2000 to 2500 revs. not so bad when under load or at low revs . does anybody have any ideas please?

Quote from: Petrus on May 22, 2024, 10:49Was looking at the effects of cooler intake air again. A bit ´frustrated´ at not being able to take the ´baffling´ around the fuel neck out.
Found a neat simple table illustrating the easy gains to be found for the otherwise not very responsive to mods  n.a. 1ZZ-FD.



Makes me rather pleased with the cool engine room temps I have achieved. Not heating up the inlet ducting under the lid adds up to the same thing.
Removing the baffles will be another small step to cooler and I hope also  a bit cleaner air.

Without me ploughing back through this admittedly splendid(but lengthy) thread, and me being lazy .....Have you managed to sort out a cold air feed of any description, that gives some gains(something other than oem)?

words are superfluous:

Quote from: Topdownman on May 23, 2024, 11:02Thats a shame.

Look forward to more reports once you start getting some miles on it.

Yeah I'm looking forward to it being daily usable!

Quote from: J88TEO on May 23, 2024, 11:27Found them!

In the post today.

Awesome!

Quote from: jvanzyl on May 23, 2024, 09:56Ah thanks!  appreciate that! I'll send you my address.

Found them!

In the post today.

US spec MR2's had a 4.312 final drive ratio in the 5 speed (C56) and SMT 6 Speed (C65), and the UK 5 and 6 speeds (C66) had a 3.941 final drive ratio.  The ratios in 1st and 2nd were the same in all of those transmissions.

Calculated top speed in 2nd for US cars is 58 mph, and with UK gearing 64 mph.  Actual speed will vary with tire size. I am not sure about the JDM gearing

Thats a shame.

Look forward to more reports once you start getting some miles on it.