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.

Looks like the time has come for me to buy an OBD2 reader and some contact cleaner.
I must familiarise myself with engine diagnostic before I could take anything apart.

Thanks for the guide lines.

Well, thanks to Amazon rush delivery the OBD2 reader I ordered last night has arrived 8am this morning!
 
It's been plugged in but sadly it could not find any pending/stored DTC. No MIL light on dashboard, no error codes stored, just high RPM...it seems the high RPM is temperature related so I need to figure out which sensor is doing that.
This is exactly what I most wanted to avoid...I just call it guess work!

Quite a lot of the time you don’t get a code and I guess your reader doesn’t show any sensor values?

You mentioned it’s temperature related, does that mean it doesn’t do it when warm?

I found this interesting website

suzukijimny.automotive-manuals.com/S8R70A1124010.html

Hope it helps

Robin

Hi Robin,

Thank you for the link . I found it's not just interesting but also terrifying how many things could cause idling issues!

The sensor shows many sensor values but obviously not all of them available for the Jimny.

Sorry, perhaps I was not clear regarding temperature.
As the temperature of the engine gets higher the RPMs does as well. The higher the temperature the higher the RPMs.

When the engine is cold the RPM is ~ 1400.
When the engine is warm the RPM settles at ~2170 and it stays there.
In between cold and warm RPM gradually increases.

On top of this sometimes it drops the RPMs down for a half a second. It does this without any obvious reason.

Regards,

Gabor

It sounds like it might be the IAC valve sticking, but a Google search also suggested the PCV valve. Both are apparently easy enough to clean and I would check the throttle body, cable and butterfly valve at the same time.

If the vehicle has been stood for a while the IAC may have become stuck especially if your engine has a few miles on it and has started to push a bit more oil mist through the engine breather.

Thank you for the suggestions.
Yes, the vehicle had been stood since July of 2020 with 80K miles on the clock.
I will have a look over the next few weekends and hopefully find out a bit more about how to tackle this situation.