donbryce

A few may have seen a previous thread I posted asking about aftermarket 'universal' sensors and how they compare with OEM 'plug-n-play' sensors. https://www.clublexus.com/forums/es3...e-cheapos.html

I'm happy to report that I got both for under $100.00, Denso, and they are the universal style. I put them in yesterday. The front one is easy, after you wrestle the stupid aluminum shield off. On the 1MZFE, these are the flange type, attached with two nuts and they fit over 2 studs with gaskets (supplied with the sensors).

The rear one is a pain though. It can just be seen from above, but all the work except unplugging/plugging in to the harness is done from below. If you have any reason to remove your exhaust pipes from the manifolds, do the rear sensor with the right (rear) pipe off the car. Lots of room to work. Otherwise, those with reasonably trim arms will have to work from 2 access spaces just above the crossmember. Even then, you'll be hard pressed to even touch the sensor or nuts.

I used a small 1/4" ratchet and 2 extensions with a flex end to remove the nuts, which stayed tight on the studs, so out came the studs as well. More on that later. I taped a small wire brush to a screwdriver to make a tool to clean the old gasket material off the manifold mounting flange. At the bench, I used the right size star (torx?) socket on the stud end and a 12mm wrench to separate the nuts from the studs. I used the same star socket to first thread the studs back in, then put on the gasket, the new sensor, finally the nuts. I taped the stud to the socket so it wouldn't fall off, like about 1/2 dozen times that stuff fell down onto the crossmember with time lost fishing it out. I mention this so you'll be prepared with a star socket to do this, as there is no way you'd ever get the gasket and sensor on without the studs in there first.

At the bench, I followed the instructions and used the supplied crimp connector and shrink tubing to attach the old connector to the new sensor wire. I used a top quality crimping tool plier to do the crimps. IMO, this would be the easiest part to do wrong, likely accounting for most follow up problems.

As to the technical questions raised in the other thread:

- According to Denso's technician, the units are sealed and have no outside oxygen/air other than that in the exhaust stream. The sensors I got were sealed, no way air goes in from anywhere, including thru the wire. How these work is still a mystery to me.

- The wire on my originals is stranded copper. The new Densos are stainless steel. Soldering is probably not the way to go, hence the special crimp connectors, and the need for the right tool to do the crimping. I was going to take the old wire out of the connector itself and put the end of the new one in, but decided it was too risky, might destroy the connector.


I now have a full tank and plan to check my mileage to see if there is any improvement.