Correct Lamda Sensor for a 2005 VVT M13A Jimny

Just thought I would share a few photos of the correct POST-CAT Lamda Sensor for my 2005 VVT M13A Jimny.
I say correct, because this very same model which was fitted into my old rusty exhaust pipe where from I could not remove the old sensor.
I had replaced the rusty Catalysator section with a brand new one which was supplied with a 'compatible' O2 sensor (bundle on e-bay...) Unfortunately it did no good because the connector was different/incompatible and once I managed to fit and the engine got a bit warm the sensor pushed the revs into 1500 RPM range instead of the normal 750 RPM. I hope this will sort out my issue. If not then the my investigation will continue.
So the new correct sensor is this (this is not the one from ebay):
 

Why not the original ones? price?

I am using the original sensors I think. or at least some original Suzuki for the second lower sensor. My cats where both broken. First cat in the manifold disintegrated and made second one full of the debris. changed to an aftermarket generic catalyst from the norwegian Halfords-alike Biltema.

Passed MOT ok, but i get the error code from unsufficient exhaust 4-5 times a year mostly from cold weather. (mine is a m16)

wrote:

Why not the original ones? price?

I am using the original sensors I think. or at least some original Suzuki for the second lower sensor. My cats where both broken. First cat in the manifold disintegrated and made second one full of the debris. changed to an aftermarket generic catalyst from the norwegian Halfords-alike Biltema.

Passed MOT ok, but i get the error code from unsufficient exhaust 4-5 times a year mostly from cold weather. (mine is a m16)

I don't know what would be the original/factory O2 sensor then.
This Denso DOX-0350 model had come already fitted with the vehicle back in 2015 when I bought the car. Never had any issues with it, all emission values were well below the limit of MOT tests in the last 5 years. Hence I thought this is the correct one. Now you made me nervous as it cost me 78.41 GBP delivered. So which one is the original if not this?

New Denso sensor has been fitted but sadly no improvement regarding high RPMs.

Can someone with greater knowledge recommend what parts might causes this?

My car spent the last 18 months in my garage. A few parts have been replaced with new ones like fuel pump, catalyc converter, lambda sensor and ignition coil packs.

Thanks in advance.

The post CAT sensor is only there to measure the performance of the CAT, as far as I know it doesn’t do anything else and doesn’t influence the fuelling and certainly not rpm.

The pre CAT sensor sets the fuel mixture and works with the MAF sensor. The MAF sensor says how much air is entering the throttle and is the starting point for the fuel injectors which are fine tuned by the pre CAT O2 sensor. Neither really set the rpm.

If you have a high idle, it looks like either your throttle body is sticking open, perhaps the cable is too tight or the slow running idle valve is sticking, if the Jimny has one.

If it isn’t the throttle cable or pedal, take the throttle body off and clean it, perhaps the butterfly valve is sticking. You can get carb cleaner, but electrical contact cleaner works well. Halfords sell a 500ml contact cleaner for £4, it cleaned the throttle body on my other car spotless of all of the black deposits.

It could also be the intake air temperature sensor saying that the air is cold and the ECU has increased the revs as it does at cold start. I am not sure if the Jimny has a separate intake temperature sensor, they seem to be combined in the MAF now.

Have you an OBD code reader, does it show any codes?

Or perhaps engine temperature sensor, the ECU thinks the engine is still cold, increasing the revs as it does at cold start.