im thinking it will be at the bottom of it where it joins to the exhaust system, see the origional manifold had threaded bolts already on, the new 1 just had holes and i think it could have been better fitted tbh

You got that wrong.....If the manifold was leaking, you'd hear it ticking. Thats what leaking manifolds sound like. A loud tick. Make sure all the bolts are tight.

engine is ticky anyways. mate. and exhaust is so loud you wouldnt notice it blowing i was thinking maybe when it expands its letting gas out sumwhere?

will fit it tbh

nope knocked no sensors i dont think

Are you sure you haven't knocked a sensor? Maybe coolant temp sensor?

You'd notice if it was not tight, you'd be able to hear it ticking. Squeaky belt won't be related to the exhaust. The heatshield stops a bit of hotness in the engine bay. I'd fit it tbh.

fitted my new manifold/de-cat and it is fine, works a charm.

have figured out though that when it gets hot im losing power at 3500 rpm.

could it be that the manifold has expanded and when the exhaust gas speeds up is excaping because i havent tightened it up enough?

ohh theres a sqeeky belt arrising, could it be related?

oh ive also left the heatsheild off, will this add to problems?:(