It is an oil pressure sender. And it's put there to avoid having it visible where it usually is in a front engine car, at the rear of the engine, just behind the intake manifold. The extension you see is needed to clear the block and fuel pump IIRC. Now here's the thing, there's a rumor that these extensions, long and unsupported, in time, can vibrate to starting to crack=no oil pressure. I don't know if this is true, if it ever happened, or if it's one in a million, but I didn't dare do it, I'd rather have the sender hideously at the back than an engine failure far away from home maybe.
Others, is this a myth or for real? Something to do with the material used for the extension?
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