frechem

I just asked APTuning, who is a UM dealer, "If I choose to leave the four O2 sensors but eliminate the other components would I get a CEL and/or would my long term fuel trims be affected? Would my mpg suffer? Or is it better to trick the ECU to think that those components are still there by using a resistor to simulate the load? This is their response, "It is for “off road” use so does not need “ all the components” if you catch my drift. No you will not get a cel and fuel trims will not be effected."

Yeah I'm in the US. Sorry I didn't mention that earlier.

This thread isn't very responsive lately or maybe poelpe don't know what I'm asking. I'll try and breakdown some of my questions so that people can understand better and hopefully this will help other people's questions in the future. There are three components on the R32 side that I can think of that either need to be coded out or use a resistor to simulate it's presence. They are parts 3,4 and 11: [ATTACH=CONFIG]81186[/ATTACH] 3 - Emission leak detection pump [ATTACH=CONFIG]81183[/ATTACH] 4 - Secondary air injection pump [ATTACH=CONFIG]81182[/ATTACH] 11 - Evap purge valve (N80) [ATTACH=CONFIG]81184[/ATTACH] Which ones can be eliminated altogether? Can the wiring for the SAI pump and purge valve be removed from the R32 harness? If they need to be kept, which ones need a resistor? Resistor size? Which wires are used for the resistor? Resistor direction? Then there is the relay on the VR harness side, the secondary air injection pump relay (111). [ATTACH=CONFIG]81185[/ATTACH] Can this be eliminated? If not, can a resistor be used? Resistor size? Which wires are used for the resistor? Resistor direction?

So if the relay needs to be kept, then what do you hook the ECU wire (the switched earth) up to? Also, do you need to run a wire from the fuel pump power?

If you've shut off everything downstream of that valve, what does it matter if that valve opens or closes? That "valve" [relay] is at the front of the [sAI] plumbing system, that's all been removed and accounted for... From an engineering standpoint, I'm willing to bet the start up circuit is built like an if/then type of statement, or a while loop... SAI only runs for a short period WHILE the coolant temp sensor reads a value. IF the O2 sensor doesn't supply the correct values in that WHILE loop, THEN it throws a code. ELSE it ends the loop. Is this logical or am I missing something?

What happened to all the regulars on here? KipVR? Kevin Bacon? I'm trying to get some electrical questions sorted.

I don't understand how the ECU will see a signal from the SAI relay if it's removed and the ECU is just controlling the ground of that relay. Is it measuring the voltage that goes through the circuit to know it completed the circuit? What exactly is happening here? This is still very confusing as to why the pump can be removed but the relay that turns it on must stay... If the ECU can be programmed to not see the SAI pump (and it's start-up effects), and we can remove it from the system, why can't the switched earth be turned off, making the relay completely useless??