How long to fit a decat downpipe?
#1
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....is it true it can take a couple of hours?
The reason i ask is i'm tempted by the H&S group buy but don't want the hassle or expense of having to change it for a Cat one at every MOT time especially if i also have a decat centre section on the car.
Does anyone have any experience of a free flow sports cat downpipe compared to a totally decatted one? Any good compared to a decat? Sound good?
many thanks. Smurfy.
The reason i ask is i'm tempted by the H&S group buy but don't want the hassle or expense of having to change it for a Cat one at every MOT time especially if i also have a decat centre section on the car.
Does anyone have any experience of a free flow sports cat downpipe compared to a totally decatted one? Any good compared to a decat? Sound good?
many thanks. Smurfy.
#2
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what car do you have?
The biggest hassle is removing the heatshield, which normally means removing the Intercooler for good access.
Then the turbo bolts/nuts can be tight, so you need to be careful they don't sheer clean off.
Someone with loads of experience would whip it off it no time, but us mortals would take at least a few hours to do it.
If you've a classic, I'd suggest removing the downpipe and then just re-fitting the centre section when you need the car MOT'd.
Not sure about the new shape though.
Stefan
The biggest hassle is removing the heatshield, which normally means removing the Intercooler for good access.
Then the turbo bolts/nuts can be tight, so you need to be careful they don't sheer clean off.
Someone with loads of experience would whip it off it no time, but us mortals would take at least a few hours to do it.
If you've a classic, I'd suggest removing the downpipe and then just re-fitting the centre section when you need the car MOT'd.
Not sure about the new shape though.
Stefan
#4
It took me two hours with occasional guidance from P20SPD and David Wallis (they were working on Steven's car and I was just relying on David's tools + their experience).
It should be easy and straightforward: remove intercooler, remove heat shield, whip off bolts, get under car and whip off bolts, remove lambda sensor... then refit
But! Some people have had bolts shear off. I had problems getting the lambda sensor out as it had been put into the original downpipe cross-threaded. I needed a few handy tools from David to sort that out. Or, more accurately, I got David to sort it out
You should pass with centre section only.
Cheers,
Nick.
It should be easy and straightforward: remove intercooler, remove heat shield, whip off bolts, get under car and whip off bolts, remove lambda sensor... then refit
But! Some people have had bolts shear off. I had problems getting the lambda sensor out as it had been put into the original downpipe cross-threaded. I needed a few handy tools from David to sort that out. Or, more accurately, I got David to sort it out
You should pass with centre section only.
Cheers,
Nick.
#6
The first time i did one it took about 5 hours but that was with some messing around and cutting the heat shield ect.
The second time i did one it took about 3 hours, again with some messing around but this time it was trying to get the damn bolts back in at the bottom of the down pipe (im sure the down pipe as about 5mm to short ?)
If you give your self all day so you dont have to rush you will be ok i think.
As has said before it should pass an MOT with just the center cat on, or have a word with an MOT tester before hand...its amazing how far £10 will get you
Andy
The second time i did one it took about 3 hours, again with some messing around but this time it was trying to get the damn bolts back in at the bottom of the down pipe (im sure the down pipe as about 5mm to short ?)
If you give your self all day so you dont have to rush you will be ok i think.
As has said before it should pass an MOT with just the center cat on, or have a word with an MOT tester before hand...its amazing how far £10 will get you
Andy
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#8
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can't remember exactly who much my Dealer charged me, but it could've been a couple of hours.
Make sure they trim and re-fit the heatshield though. Mine didn't so ended up doing it myself. Only took minutes to trim with some tin-snips, but I did have a bit of a hassle fitting the thing.
The bolts were fecking tight as. I use a std socket wrench and just couldn't budge them and no amount of WD40 helped either.
Then I bought a much longer socket bar and with the extra leverage they came undone easily. So, if you want to try it yourself, just make sure you've a good quality socket and a long enough bar to give you good leverage. Use plenty of WD40 and leave the bolts/nuts soaking for an hour (maybe even overnight) and you shouldn't have any problems.
Oh, a good spanner for the Lambda probe and soaking in WD40 will help it come undone too. Make sure the exhaust is stone cold before trying to remove that.
Stefan
Make sure they trim and re-fit the heatshield though. Mine didn't so ended up doing it myself. Only took minutes to trim with some tin-snips, but I did have a bit of a hassle fitting the thing.
The bolts were fecking tight as. I use a std socket wrench and just couldn't budge them and no amount of WD40 helped either.
Then I bought a much longer socket bar and with the extra leverage they came undone easily. So, if you want to try it yourself, just make sure you've a good quality socket and a long enough bar to give you good leverage. Use plenty of WD40 and leave the bolts/nuts soaking for an hour (maybe even overnight) and you shouldn't have any problems.
Oh, a good spanner for the Lambda probe and soaking in WD40 will help it come undone too. Make sure the exhaust is stone cold before trying to remove that.
Stefan
#9
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Its the first time the OEM d/pipe comes off that is the problem. Bolts are rusted or seized and it's a pig of a job. Must have taken me 4 hours first time. Had 3 heat shiled bolts shear
For first time removal I'd advise day before spraying 3 in 1 on heat shield bolts then take off IC. Come back to heat shield and take off bolts - bet one or two shear though.
Spray more 3 in 1 that night night on O2 sensor, five turbo nuts, bolt to gearbox, hanger bolt and the two bolts with springs on at join to mid section. Theres also a little heat shield on the up pie.
Start undoing nuts next day.
Disconnect the O2 sensor wiring but leave in place until the d/pipe is out - you'll then have a better chance of removal/putting back in without damaging the threads.
I'd recommend that the first time it is off then the turbo studs are wire brushed and oiled or replaced with OEM studs. Also start with a new turbo gasket.
If all the nuts are then coated with high temp grease then removal the second time around is much quicker. Best I can do is an hour.
Just make sure that you have a stock of good quality nuts and bolts.
Nick
1997 Forester S/tb
For first time removal I'd advise day before spraying 3 in 1 on heat shield bolts then take off IC. Come back to heat shield and take off bolts - bet one or two shear though.
Spray more 3 in 1 that night night on O2 sensor, five turbo nuts, bolt to gearbox, hanger bolt and the two bolts with springs on at join to mid section. Theres also a little heat shield on the up pie.
Start undoing nuts next day.
Disconnect the O2 sensor wiring but leave in place until the d/pipe is out - you'll then have a better chance of removal/putting back in without damaging the threads.
I'd recommend that the first time it is off then the turbo studs are wire brushed and oiled or replaced with OEM studs. Also start with a new turbo gasket.
If all the nuts are then coated with high temp grease then removal the second time around is much quicker. Best I can do is an hour.
Just make sure that you have a stock of good quality nuts and bolts.
Nick
1997 Forester S/tb
#10
As stated it is sometimes very difficult to undo the nuts on the turbo. I have got a decat downpipe and a free flow cat in the centre pipe which always get through the MOT test and does not cost any significant power. Use plenty of WD40!
Les
Les
#11
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As above first time is the hardest took me 4 hrs seized bolts on turbo used a dremel to cut nuts off and then cleaned studs up now takes me about an hour to change
definately worth it
Mark
definately worth it
Mark
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