Emissions Questions

[PoorManQ45]

I was under my Q45 today and I have a few questions about the emissions system.

I remember reading somewhere that placing the Catalytic convertors closer to the headers will lower emissions. I think they said it was because the cats heated up quicker.

1. Will placing the cats closer to the headers reduce emissions? Possibly next to the transmission pan.

2. Would there be any problem with moving the O2 sensors a little farther down on the exhaust? So they would be easier to change.

Unrelated to Emissions but I want to know

3. Where is the oil pressure sending unit on the 92 Q45?

4. Does it actually send the oil pressure to the ecu. Or does it just alert the ECU when the oil pressure is too low?

[Q45tech]

Oil pressure sender is just a switch with a weak spring that turns the light on when pressure drops below 3-4 psi from minimum of 14psi hot idle to the 60-100 psi you get at high rpms.Oil pressure lights work the same on all cars and have since the 1950's, now real gauges are another matter.

O2 cannot be moved without disrupting the calibration. Even mixing of all 4 cylinders........to close to cat and they overheat and fail too far away and they don't heat up enough ......even with the built in warmers [called heaters]

Pre [1st] cats are composed of different materials to heat up quickly then expand and essentially get out of the way as the main cat heats up and takes over the real work. Position and distances are critical to meet warm up/cold start emissions.

[PoorManQ45]

Oil pressure sender is just a switch with a weak spring that turns the light on when pressure drops below 3-4 psi from minimum of 14psi hot idle to the 60-100 psi you get at high rpms.Oil pressure lights work the same on all cars and have since the 1950's, now real gauges are another matter.

I am planning on installing a real Oil Pressure gauge with sending unit. Will removing the stock sending unit cause any problems?

[Q45tech]

Find a pipe tee and hook both up or just disco the oem sensor lead and the oil light will never come on.

[PoorManQ45]

Where is the sending unit? I was reading the FSM and it showed the sending unit being on the driver side between two of the header tubes. I looked where the FSM said it should be and I didn't see anything.

Now, when I looked from underneath the car, I saw what appeared to be a sending unit below the driver side manifold. It a 1 or 2 wires coming out of it.

Is that where the oil sending unit is?

Also, you said I could just disconnect/replace the OEM sending unit. Will the ECU "notice" this.

Do you have any suggestions of which oil pressure gauge/sending unit would give me a very accurate reading?

[elwesso]

I tired to remove mine... Its on the block, and you can barely reach up there.. Your head will be about even with the transmission pan, on the drivers side in order to see it... Its just a little thing sticking out of the block.... 2 wires coming from it.....

I unplugged (or rather forgot to plug mine in) and the oil light just stayed off..... By just unplugging it youd be safe, oil light wouldnt be on...