PDE Up-up pipe install Q&A

[Mike]

I bought a used, but in great condition PDE Up-Pipe on ebay a while back for
$50 and am now ready to do the install. But I have a few questions...

It has an EGT bung in it...
(here's a pic)
http://www.oakos.com/Merchant2/merc...de=355&Product_Code=PDE-001&Category_Code=222

1) Some people suggest that the added heat from the missing cat might cause
premature failure (and that parts could come off and get into the turbo).
Would it be better to seal it off and not install the EGT sensor? The
NASIOC forums seem to be inconclusive.

2) Gaskets - factory or copper?
http://www.oakos.com/Merchant2/merc...355&Product_Code=CRUUPPGASK&Category_Code=222

3) What about wrapping it in exhaust tape?



Mike

 

[CompUser]

1) Some people suggest that the added heat from the missing cat might cause
premature failure (and that parts could come off and get into the turbo).
Would it be better to seal it off and not install the EGT sensor? The
NASIOC forums seem to be inconclusive.

You've got less heat, not more, without the
cat...cats generate heat (oxidation process).

3) What about wrapping it in exhaust tape?

I thought you were worried about heat?!?
Some like wrap, some don't. One truth is all
manufacturers void warranty coverage on cracks,
etc if components were wrapped. That should tell
you something ;-)

 

[mulder]

I bought a used, but in great condition PDE Up-Pipe on ebay a while back for
$50 and am now ready to do the install. But I have a few questions...

It has an EGT bung in it...
(here's a pic)
http://www.oakos.com/Merchant2/merc...de=355&Product_Code=PDE-001&Category_Code=222

1) Some people suggest that the added heat from the missing cat might cause
premature failure (and that parts could come off and get into the turbo).
Would it be better to seal it off and not install the EGT sensor? The
NASIOC forums seem to be inconclusive.

With a catless uppipe you no longer need the EGT probe. It is only
there to monitor the temperature of the catalyst in the factory
uppipe, which you have now removed. While it is possible to put the
probe back in if there is a bung for it, it won't serve any purpose
and it is fairly common for them to fail a short time after being
reinstalled in a catless pipe. The cause of the failures may not be
temperature but the increased exhaust flow, since in the OEM pipe the
probe is located within the catalyst matrix and now it will be exposed
to the full exhaust flow.
You're best off sealing the bung with a bolt and doing the "resistor
mod" by installing a 2.2K ohm resistor in the connector where the
probe now connects.

2) Gaskets - factory or copper?
http://www.oakos.com/Merchant2/merc...355&Product_Code=CRUUPPGASK&Category_Code=222

3) What about wrapping it in exhaust tape?

Probably best off using factory gaskets, and be sure to torque the
bolts properly. Don't be surprised if it leaks anyway, they often do.

 

[TG]

Most people with modified turbo cars like to run an EGT...and not to monitor
the temperature of the catalyst. The temp is a great diagnostic tool to keep
an eye on pre-ignition, help decide boost level, etc. TG

 

[mulder]

Most people with modified turbo cars like to run an EGT...and not to monitor
the temperature of the catalyst. The temp is a great diagnostic tool to keep
an eye on pre-ignition, help decide boost level, etc. TG

True, but the question here is what to do with the factory EGT probe
when installing a catless uppipe. You're correct that once the car has
been modified for more boost and power it's a good idea to monitor the
EGTs with a gauge, however this requires an aftermarket probe along
with the gauge, and the probe should be mounted in the exhaust
manifold rather than the uppipe. The factory location is not ideal for
this purpose, and the existing probe isn't compatible with aftermarket
gauges.

 

[Mike]

So should i plug it or insert the probe into the new bung?

 

[mulder]

So should i plug it or insert the probe into the new bung?

I say plug it, remove the probe completely and do the "resistor mod".
Should you decide to put the probe back anyway, don't be surprised to
see a CEL in the near future, probably with a P0546 code indicating a
blown probe.

 

[Mike]

I just realized that the bolts that come on the up-pipe are not there...

Obviously the prev. owner did not give them up when he sold me the item.
Can the bolts be taken from the factory up-pipe (I was thinking of using two
nuts backed tightly into each other and then using them to unbolt the studs
from the OEM piece). Otherwise, since the PDE unit is threaded couldn't I
just go buy five new 10x1.25 Stainless Steel bolts for use?

Mike

 

[TG]

I stand corrected, thanks. TG

True, but the question here is what to do with the factory EGT probe
when installing a catless uppipe. You're correct that once the car has
been modified for more boost and power it's a good idea to monitor the
EGTs with a gauge, however this requires an aftermarket probe along
with the gauge, and the probe should be mounted in the exhaust
manifold rather than the uppipe. The factory location is not ideal for
this purpose, and the existing probe isn't compatible with aftermarket
gauges.