Do it wrong, do it
twice. Do it right,
do it once.
Join Date: Mar 2011
Location: New Zealand
How smart is the emissions management system.
I am faced with a challenge. The challenge is to save a lot of money by not getting my 156 2L JTS tuned once I replace the catalytic converters with a performance manifold. It wouldn't be so bad if I didn't have lower wishbone replacement on my mind.
I have heard about spark plug defoulers but I don’t think their behaviour can be adequately controlled.
I have found out how to easily make an electronic simulator which generates a square wave with a 0.9v amplitude and 3 second duration. It could be adapted further to change the reference voltage if necessary. Has anyone had experience with electronic simulators?
There is a lot of inconclusive information out there on what is the acceptance criteria for post cat oxygen sensors and how they affect the fuel trim. So I am looking for any information that may help me make an informed decision about the effectiveness of simulators.
I have read in the service manual that post cat sensors do have an effect on the fuel trim but it does not state how they feedback into the system. I assume they cannot provide an absolute value for the fuel ratio due to inconsistencies present within the catalytic converters so their effect must be somewhat limited.
If I understand correctly, providing the engine management system with a post cat oscillating signal around 0.45v would have the same effect as tuning out the post cat signal during a remap. The only advantage remapping has, that I can see, is the engine will have improved mapped parameters for whatever changes have taken place. I am guessing that the effectiveness of an engine with simulators instead of a remap is highly dependent upon the accuracy of the pre cat sensors.
Any thoughts? Other than put in a new converter as I have unfortunately been there and done that.
(Mechanical Engineer + Mechanic - Alfa)*time = ln(Bad News)