So far I have replaced the top 'y' and connecting 's' pipe, but after a couple of days of smooth running I've gone back to my original problem of occasional limp home, flat spots 1500-2000 rpm and feeling of low power.

I've opened up the joint between th 'y' &'s' pipes and again have mayo filling the pipes. And so I'm suspecting the 't' piece connector under the inlet manifold. So a couple of questions,

Anyone know the part number for the 't' piece? Is it a dealer only part or are there suppliers anyone can direct me to?

Secondly to get to it I know it'll be easier for me to pull the n112 & n249 out the way ( something I'm hardly gutted about)

Can I remove those, fit the resistors etc then re install the secondary air for now simply to save a bit of money then remove the secondary air when I can get the blanking plate?

Should be no problem get the t piece and elbow clear out the crank case breather valve and do the deletes as per bowders tech thread. You can leave the SAI in place just be careful cutting the vac pipes as you'll need some of them for the SAI.

Should be no problem get the t piece and elbow clear out the crank case breather valve and do the deletes as per bowders tech thread. You can leave the SAI in place just be careful cutting the vac pipes as you'll need some of them for the SAI.

Cheers. Just thought I'd check because the threads I've been through like bowders all remove the SAI

When you cut the vac pipes to the N112 and the N249 just don't cut the one to the SAI combi valve, there may be some other bits that differ slightly try and find robs vac pipe schematic that shows all the different pipes and where they go.