Fitting a decat downpipe help, please

Ric McLaughlin

V-Limited Member
Hi guys,

Seeing as how 'tis the season to spend time with loved ones and family, I had hoped that I could spend this weekend fitting my new decat downpipe to my '99 Type R. However, I can't seem to get any of the bolts connecting the existing cat downpipe to the back of the turbo loose. Has anyone else experienced this?

Space is obviously limited but I have removed the intercooler and I've soaked them as much as possible in WD40 but there's absolutely no give in any of them.

This is the sort of job that I'd normally consider safely within my mechanical remit and I'm keen not to go through the faff (or wait, or expense) of taking the car into a garage to get it done. I thought it may be worth asking on here to see if there are any tips which may help before lifting the phone and admitting defeat.

Thanks in advance for any and all help.

Race Altered

V-Limited Member
You just need to be harsh with them bolts, long ring spanners help or a braker bar or a pole on the end of the spanner, another tip is blowtorch on the nuts get heat into them,get your spanner on and hit with a lump hammer,

once you tell yourself they are coming off you will get them :thumb


STI V2 555 / V3 STI
Ric, I've done hundreds of downpipes on Subaru and I would recommend the following:

Take heatshields off
Spray nuts with penetrant (including those underneath)..let it sit
Heat nuts with torch if necessary after that and use this double box wrench method on them (not my video)
Watch your knuckles! Put a towel around any place you might punch if the nuts come loose.
Reinstall with high temp penetrant

Ric McLaughlin

V-Limited Member
Thanks for the replies!

I've ordered a couple of extra long 14mm spanners to try and get a bit more leverage. I've (hopefully) got a bit of time to try and get back at it again towards the end of the week, I'll let you know how I get on.

Ric McLaughlin

V-Limited Member
That was employed too! That tool meant that I could get a 21mm spanner on the back of it plus a 22mm in the aforementioned illegal position. Currently on the run in South America.