Catalytic Converters.
#41
05-23-2017, 12:19 AM
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Join Date: May 2017
Location: Auckland
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#42
05-25-2017, 07:58 AM
Senior Member
You cannot have it both ways.
The downstream O2 sensors serve two functions, they check the efficiency of the catalyst, AND they are used for fuel managment ("used in conjunction with the ECM and the HO2 sensor 1, the HO2 sensor 2 aids closed loop fuelling control")
Makes
If you fit "sport" cats, they do not clean the exhaust gas as efficiently as the stock cats, so you will get a CEL and P0420/P0430 codes.
If you try to "fool" the downstream sensors with an extension or minicat, you stop the CEL and P0420/P0430, but you screw up the fuelling. Same goes for relocating the O2 sensors or any other deviations from the factory arrangement of the downstream O2 sensors.
There are some explanations in this thread https://www.jaguarforums.com/forum/x...-remap-140980/ where we removed the mincats from the downstream sensors, and changed the tune in the car so that the catalyst efficiency monitoring is disabled.
So the downstream O2 sensors are working correctly (physically in the exhaust gas stream, getting accurate measurements) but there are no P0420/P0430 codes being set, because they are effectively disabled.
This is the "right" way to do it.
The downstream O2 sensors serve two functions, they check the efficiency of the catalyst, AND they are used for fuel managment ("used in conjunction with the ECM and the HO2 sensor 1, the HO2 sensor 2 aids closed loop fuelling control")
Makes
If you fit "sport" cats, they do not clean the exhaust gas as efficiently as the stock cats, so you will get a CEL and P0420/P0430 codes.
If you try to "fool" the downstream sensors with an extension or minicat, you stop the CEL and P0420/P0430, but you screw up the fuelling. Same goes for relocating the O2 sensors or any other deviations from the factory arrangement of the downstream O2 sensors.
There are some explanations in this thread https://www.jaguarforums.com/forum/x...-remap-140980/ where we removed the mincats from the downstream sensors, and changed the tune in the car so that the catalyst efficiency monitoring is disabled.
So the downstream O2 sensors are working correctly (physically in the exhaust gas stream, getting accurate measurements) but there are no P0420/P0430 codes being set, because they are effectively disabled.
This is the "right" way to do it.
#44
05-28-2017, 06:45 PM
You have the downstream sensors installed in a correct position, that the sensor tips are in the gas stream?
#46
05-28-2017, 09:45 PM
Well that's good.
I know of an S-Type R that was fitted with the Magnaflow 200 cell cats, with the sensors also in the correct position, and it hasn't thrown the P0420/P0430 yet.
Yet other cars with 200 cells have thrown the codes... so I guess maybe there is something special about those Magnaflow cats then...
I know of an S-Type R that was fitted with the Magnaflow 200 cell cats, with the sensors also in the correct position, and it hasn't thrown the P0420/P0430 yet.
Yet other cars with 200 cells have thrown the codes... so I guess maybe there is something special about those Magnaflow cats then...
#48
05-31-2017, 09:09 AM
Member
As explained by my trusted mechanic who steered me away from aftermarket cats, the precious metal coating on the cheaper aftermarket units are usually so thin that they last a very short time before throwing codes and then require you to replace them again. He was adamant that I go OEM when one of my cats began to rattle.
#51
08-25-2017, 04:11 PM
Veteran Member
On the RHS standing in front of car.
I have Paramount 200 cel cats and do not get any cel codes.
I originally installed the mini cats and noticed huge volumes of smoke when accelerating hard.
Took them out and no problems since.
Changed out the upstream O2 sensors today, 3rd time in several weeks, will see how it runs tomorrow.
All 4 sensors are Denso recommended for my car.
First upstream replacement produced a code. Reinstalled original and replaced today with a set of new Denso sensors.
I have Paramount 200 cel cats and do not get any cel codes.
I originally installed the mini cats and noticed huge volumes of smoke when accelerating hard.
Took them out and no problems since.
Changed out the upstream O2 sensors today, 3rd time in several weeks, will see how it runs tomorrow.
All 4 sensors are Denso recommended for my car.
First upstream replacement produced a code. Reinstalled original and replaced today with a set of new Denso sensors.
#52
09-06-2017, 08:22 AM
Senior Member
DIY
In your opinion, is changing the cats in my garage with the car on ramps something I can tackle? I ordered the catalytic converters and downstream sensors since I'm failing emissions and I was wondering if this job was easily accomplished by a somewhat skilled person with the right tools.
Thanks.
Thanks.
#53
09-06-2017, 09:31 AM
Veteran Member
In your opinion, is changing the cats in my garage with the car on ramps something I can tackle? I ordered the catalytic converters and downstream sensors since I'm failing emissions and I was wondering if this job was easily accomplished by a somewhat skilled person with the right tools.
Thanks.
Thanks.
I used drive up ramps and did the work quite easily except for one stud that was cross threaded into the exhaust manifold.
I had to disconnect both rear band connections to the rest of the exhaust system in order to get the cats in and out. Just doing one at a time does not give you enough freedom of movement.
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#54
09-10-2017, 12:25 PM
Senior Member
#55
10-06-2017, 05:20 PM
Have you installed your Mina pulley yet? I've got mine sitting on the bench waiting to go on.
I replaced the cats with aftermarket ones, DEC brand. The job was relatively simple. The only hiccup was one the cats pipe diameter was a little too big to slide into the exhaust pipe. Nothing a muffler shop couldn't fix. The car sounds louder and meaner. passed emissions no problem.
#57
10-07-2017, 07:42 AM
Veteran Member
My car has been running just fine until the other day when it threw lean codes for both banks. Followed by restricted performance.
I had done a few really hard take offs just prior to this happening.
Luckily found the cause very quickly however totally puzzled as to how the vacuum tube came off! Engine mounts seem to be fine.
Anyway this is the question I have:
Would removing one resonator and adding an X-pipe improve power with the setup I have?
I have: 10% pulley
Slightly modified and upgraded SC
200 cel cats (Paramount)
Stage I intake
Extra SC cooling with upgraded pump.
Clean Charge coolers with oil catch can.
New O2 sensors
Relatively new plugs
Oh and I do have the Quaiffe LSD which helps me apply the power that I already have.
The only issue that I probably have is that the exhaust valves almost certainly have carbon on them since my charge coolers were so clogged before I cleaned them.
I had done a few really hard take offs just prior to this happening.
Luckily found the cause very quickly however totally puzzled as to how the vacuum tube came off! Engine mounts seem to be fine.
Anyway this is the question I have:
Would removing one resonator and adding an X-pipe improve power with the setup I have?
I have: 10% pulley
Slightly modified and upgraded SC
200 cel cats (Paramount)
Stage I intake
Extra SC cooling with upgraded pump.
Clean Charge coolers with oil catch can.
New O2 sensors
Relatively new plugs
Oh and I do have the Quaiffe LSD which helps me apply the power that I already have.
The only issue that I probably have is that the exhaust valves almost certainly have carbon on them since my charge coolers were so clogged before I cleaned them.