Posted 04 February 2005 - 03:45 PM
your FC will become bad if the lambda light comes on because the ECU will
try to compensate for whatever it thinks is wrong.
Posted 04 February 2005 - 05:26 PM
The oxygen sensor before CAT (Main O2S) is for close-loop engine
operation, while the O2S after CAT (Sub-O2S) is used to monitor the CAT.
When CAT is OK, the socillating signal from Main O2S and Sub O2S is much
different. At +/- 2500 RPM, the main O2S oscillate 8 times during 10
seconds, while sub O2S oscillate once. When sub O2S oscillate the same as
main O2S means that the CAT fail (Main and Sub O2S reading the same
concentration of O2), bcoz no conversion gas passing through CAT, same
oscillation as a result and lambda sersor light-on. This if you install 2
A/F meter for both Main and Sub O2S, you directly point out the fault.
But if no A/F meter installed, have to check the faulty code, wether CAT
failure or merely O2S failure.
Since the CAT has been already removed, the faulty code should correspond
to the CAT Failure.
Did you remove all the O2S ?. If it is the case, ECU enrich the fuel and
your engine will running rich (as kenari1 also said). But if you still
have Main O2S, logically (for ECU ofcourse) the car run based on main O2S
This problem won`t come out for volvo 200/700/900 series, bcoz only 1 O2S
configuration before CAT.
Posted 04 February 2005 - 06:15 PM
No more. When the lambda light first appear, I send to PA and they did the
electronic tuning & diagnostic. They subsequent to that change something
near my manifold (sorry, I could no longer remember what they change) and
since then the lights is off.
The only things that annoys me is the rattling sound coming from CC.
Consumption wise, not much difference then and now.
Posted 04 February 2005 - 07:51 PM
check this out
Posted 04 February 2005 - 11:34 PM
Go to woksyop n get the OBD11 analyzed your O2 sensor/s...there's
possibility that your sensor kong...did he do the welding with the sensor
installed???? if yes than that's it! the sensor has max operating
temperature certainly not the kind of those of coming from welding works.
A good exhaust installer would know this fact or experienced thru his own
bad experiences before...
Posted 04 February 2005 - 11:56 PM
didn't realize there was two. Gone case lah like that. If I were to
purchase a new car, does it come with the sensor?
And if the sensor is kaput, how? The FC would be really bad?
Posted 05 February 2005 - 12:29 AM
I did not remove any sensor. Not the one in front but not sure about the
one after the cat. Don't evern know exactly where the sensors are located.
Anyone know how much the sensor cost? I will be going down to KL in the
morning, so maybe I will drop by at PA to get the sensors checked. Money.
Posted 05 February 2005 - 02:43 AM
The main O2S shall be located as close as possible to exhaust manifold.
If yours is Turbo, main O2S shall be located at DP behind Turbo before
CAT. It has 4 wires, 2 white, 1 black and 1 Grey, the connection socket
to ECU harness is flat. Check it first, if still there, don`t worry about
As for Sub O2S, I am not certain where it is located. Since S70 is the
first in the world which uquipped with Three-Way CC, the Sub O2S shall be
located somewhere between CC and silencer. This also got 4 wires, same as
main O2S but socket connection to ECU harness is rectangular or flat same
as main O2S depends on year make.
If this is the case, both your O2S are still there and both main and sub
O2S send signal to ECU with the same oscillation, Lambda sensor light-on
as a result.
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
The cost of O2 sensor (ori, actually from BOSCH) for S70 ranging from US$
140 to US$ 200 (RM 560 to RM 800). I don`t have idea the price at PA. I
think your O2S should be OK.
You might use Wira`s O2 Sensor 4 wires from BOSCH which cost only RM 170,
or get used O2S from V850, cost RM70 at hakitrade Subang.
I bought used O2S at hakitrade for my 940, clean-up with injector
cleaner, work well. But this is not recommended. I just try, since the
most O2S faulty is due to carbon build-up, that`s why I cleaned-up with
injector cleaner. Predicted O2S TBR (Time Between Replacement)is 150,000
You can check your O2S by using low scale VOLTMETER.
1. Connect (hook-up) positive lead from Voltmeter to black wire of the
O2S or green wire running to ECU.
2. Connect negative lead from voltmeter to ground (body).
3. Start the engine and wait for about 3 minutes.
4. If O2S ok, the volmeter will oscillate from 200 mV to 700 mV and back
to 200 mV.
5. Increase the rpm up to 2500, you will notice that the voltmeter
oscillate 8 times for 10 seconds. Less than that O2S is faulty. If no
oscillation on voltmeter, your O2S dead.
....Sub O2S does not play a role in mixture adjustment but merely acts as
an alarm in the event of catalytic converter failure (monitoring
function) ...... if removed, don`t worry about the FC.
Posted 05 February 2005 - 05:10 AM
Wait and see what PA`ll find out .... waiting for your update.
Posted 16 February 2005 - 01:18 PM
seemed to have come from the throttle sensor instead. Drove it for a week
and then the problems set in. At stationary, the engine went really weak to
the point of stalling. At normal speeds, the RPM goes up and down, even
when at a constant speed. Took it back to PA yesterday and had it checked
again. Replaced the throttle sensor at RM480 inclusive of labor. It's is
much more responsive now and accelerator is much lighter compared to before.
I was told that a lot of people chop off their CC.... Maybe you can ask
around... Only thing is I smell petrol, mainly because there is no CC to
burn off excess fuel.