Discussion
Those of you that have gone the De-CAT route; any idea what happens to the Lambda sensors? Are they still there but in the 'bypass pipes' whatever they are!? Or are they flung unceremonially into the bin along with the old CATs and the ECU adjusted/adjusts itself accordingly?
Cheers Simon
Cheers Simon
perhaps the alternative would be to fit air flow meters (the cat cars don't need them) but then I think you need to replumb (take out) stuff like the MAP sensor etc, and I'm not even sure that the ECU fuel map is the same - I suspect that a non-cat ecu would also be required.
The lambda sensors should be upstream of the cats (ie between the engine and the cats) - are yours fitted into the cats? I can't see how that would work to be honest - the ecu can't map the fuel mix on the basis of exhaust that has been even partially cleaned.
Where are your cats fitted? I didn't think they would fit the pre-cat manifolds - they are too long.
Does your car have air flow meters?
The lambda sensors should be upstream of the cats (ie between the engine and the cats) - are yours fitted into the cats? I can't see how that would work to be honest - the ecu can't map the fuel mix on the basis of exhaust that has been even partially cleaned.
Where are your cats fitted? I didn't think they would fit the pre-cat manifolds - they are too long.
Does your car have air flow meters?
It's a conversion to a later 4.0l cologne which is '97 so is fully OBD-II compliant and which I was hoping to use my existing manifolds. It actually should have 4 lambda sensors; 2 on each side 1 before and 1 after the cats as you suspected. I thought I might be able to get away with fixing the little buggers in anywhere as obviously I don't have to have the CATs fitted in an '88 TVR so it wouldn't matter where the sensors are fitted as they will read the same anyway. The other option is to leave them out completely which would mean the ECU running in LOS mode permanently and would be I'm told, not great for fuel ecomony!
LOS mode is not recommended, you're right. I think that fitting airboxes, changing the ecu (which would, I am sure, need remapping) is just too much hassle.
I think the easiest option would be to drill the bypass pipes and weld a nut on with the right thread for the sensors. I say this on the basis that the bypass pipes can be drilled and welded before you put them on - they can also be rotated when fitting to get the sensor in the best position.
AND!! If you drill the manifold and it goes wrong, they are just a bit more expensive!
I think the easiest option would be to drill the bypass pipes and weld a nut on with the right thread for the sensors. I say this on the basis that the bypass pipes can be drilled and welded before you put them on - they can also be rotated when fitting to get the sensor in the best position.
AND!! If you drill the manifold and it goes wrong, they are just a bit more expensive!
Gassing Station | S Series | Top of Page | What's New | My Stuff