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Catalytic Converter


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#11
vol940

Posted 23 February 2005 - 11:17 PM

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Another method to check a clogged CC without removing the CC :

As kaminski said, remove the O2 Sensor, but this time connect a pressure
gauge (1 to 10 or 15 psi gauge scale) into the O2 sensor port.

Bought WIKA Pressure gauge (1 - 15 psi scale) RM 28.

At idle, increase the RPM up to 2500, if the pressure indicates geater
than 1.75 - 2 psi, then the CC already clogged. The maximum back pressure
shall be less than 2 psi.Tongue

#12
kaminski

Posted 23 February 2005 - 11:27 PM

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Glad you sorted out the cc diagnosis...is anyone keeping all this
valuable problem solving?

#13
glock19

Posted 25 February 2005 - 07:44 AM

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The BIG question still remains - would the lamdba lamp come up without the
cc for the Volvo ? I think the 940 have only one sensor before the cat, so
it might not show but what about the newer ones like 850/S/V models which
have 2 sensors ?

Kaminski, as for the troubleshooting guide, you can out them in your
website Big Smile and vol940 will put it into the 555 book.

#14
vol940

Posted 25 February 2005 - 12:43 PM

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Glock19,

The answer of the BIG question are as follows :

1. Vehicle equipped with only 1 O2 sensor (before CC), no problem for
lambda warning light (like mine, 940).

2. Vehicle equipped with 2 O2 Sensors (before and after CC), has the
following objective :

a. O2 Sensor Before CC (Main O2 Sensor) : used for Fuel Management.
b. O2 Sensor After CC (Sub O2 Sensor) : used for Monitoring of CC
(Emission Control - Environment Issue).

When we remove the CC and replaced with straight pipe, the lambda sensor
could light-on, but this doesn`t effect the performance. The following
are the Faulty code related to Catalytic Converter based on Sub O2
sensing (O2 sensor AFTER CC),

4-4-3 Catalytic Converter Efficiency.
5-4-4 Misfire on more than one cylinder, catalyic converter damage
5-4-5 Misfire on at least one cylinder, catalyic converter damage
5-5-1 Misfire on cylinder no. 1, catalyic converter damage
5-5-2 Misfire on cylinder no. 2, catalyic converter damage
5-5-3 Misfire on cylinder no. 3, catalyic converter damage
5-5-4 Misfire on cylinder no. 4, catalyic converter damage
5-5-5 Misfire on cylinder no. 5, catalyic converter damage

These faulty codes do not exist on vehicles equipped with only 1 Oxygen
sensor (LH 2.4).

If the faulty code is 2-1-2 (same for LH 2.4 and Motronic 1.8), then this
deals with Main Oxygen Sensor (O2 sensor before CC), the performance will
be effected, "High FC and Driving Problem" - Up to 30% wasted Fuel.

Current problem on my 940 : Leakage On Turbo - Manifold Joint - City
driving got only 6 km/ltr.
Cool

#15
SA6

Posted 25 February 2005 - 04:21 PM

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vol940, I think is best to keep your sensor at original status, if there
is 2 better keep the second one even if there are no performance effect. I
beleive both the sensor are directly link to your ECU therefore, tempering
it may effect your ECU reading function in the long run.

On the manifold leak, if it is becuase of gasket, than just get a gaslet
sealent will do the trick. I had experience manifold leak to my NA 740 and
eventually a new gasket also won't help. Finally I get a tube of gasket
sealent and it managed to 100% stop the leak. Such sealent is not harmful
to CC or O2 sensors, is cheap less than RM20, good luck..

#16
vol940

Posted 25 February 2005 - 08:04 PM

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SA6,

Many thanks bro...

Since mine has only 1 O2 sensor, seems there is no problem with the
performance, I just removed the CC and the restrictor behind CC, then
replaced with straight pipe.

As for the gasket sealant, where did you get it ?. Mine has no gasket for
Turbo/monifold joint, try to duplicate your experience using gasket
sealant. This leakage cost me on FC.Frown

#17
SA6

Posted 25 February 2005 - 10:13 PM

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Dear vol940, as regard to the gasket sealant, I got mine from a local
speaparts shop. The sealant work as gasket so you need to apply between
the manifold. When hot the sealent will expand a little bit than immy
harden, it really an amazing stuff !! I hv to admit Volvo are very
sensitive to leak. I do felt the different after fixed the leak from the
manifold joint. Our RWD Volvo are heavy fuel drinker in city but in the
long distance some pretty good condition once can get about 75km to 80KM /
Rm10 ringgit of fuel !! good luck

#18
hohgch

Posted 25 February 2005 - 11:51 PM

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I took my cat out too, unfortunately. I was having lambda light problems
initially and thought the welder screwed up the O2 sensors. But fortunately
not because when I took it to PA for OBD its fault was at the throttle sensor.

So far, lambda light not visible. Touch wood. Approve

#19
vol940

Posted 26 February 2005 - 12:11 PM

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SA6,

Sorry to ask a question, did you open the joint first then apply the
sealant or just insert/inject the sealant to the joint ?. Just bought the
sealant at spare-parts shop --- RM10. Thanks a lot.

FC also suffered a bit for long distance 70 km / RM10.

-------------------------

hohgch,

I suspected your O2 sensors, bcoz just after you replaced your CC the
lambda warning light came up. BTW, glad to hear that you solved the
problem.

--------------------------



#20
SA6

Posted 27 February 2005 - 03:53 PM

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vol940, yes I took out the manifold, you need to dismentle the manifold
and if possible try to scrab of any carbon deposit or rush in between,
apply the sealant than assemble it back. Run the engine for just few
minutes the sealant will begin to hard. Don't misunderstood the sealant as
glue, they work excately as gasket so they need to apply in between and
tighten. good luck