Fitting an O2 sensor to a car?

[Fab5Freddy]

I would recommend taking the car to some one who has diagnostic equipment to view live data of your engine management and sensors (and who understands what the data is telling them)They can then tell if it is a O2 sensor fault or some thing else ,I know you are trying to save costs but you can be chasing your tail if not.

I' starting to think along those lines too, but I don't have a garage/mechanic I trust since a regular one retired. I took another vehicle to a different local one after the good garage closed, and never again...

 

[Keithmac]

Introduce a lean condition (Pull the brake booster pipe off) while running and watch the sensor voltage reaction on live data.

I've seen countless times the sensor pegged rich or lean is something completely different fueling wise and the sensor was just doing it's job

You could have an injector partially stuck open for instance.

It could well be the sensor itself but you need to test to verify.

That's where a lot of garages go wrong, just blindly following fault codes, firing the "parts cannon" and hoping for the best..

 

[Fab5Freddy]

Introduce a lean condition (Pull the brake booster pipe off) while running and watch the sensor voltage reaction on live data.

I've seen countless times the sensor pegged rich or lean is something completely different fueling wise and the sensor was just doing it's job

You could have an injector partially stuck open for instance.

It could well be the sensor itself but you need to test to verify.

That's where a lot of garages go wrong, just blindly following fault codes, firing the "parts cannon" and hoping for the best..

I dont know much at all about car engines, but I am starting to realise that this is a bit more complex than I might have guessed. Diagnosing faults is a skilled game
I just wish I knew a garage/mechanic that was a) good b) trustworthy c) with the tech to do all the tests to diagnose it

 

[Keithmac]

It should be in Open Loop at Wide Open Throttle anyway, I suppose the Long Term Fuel Trims may be used as a modifier in the Open Loop fuel maps?.

What did the old plugs look like, black on the ends?.

If you do decide to fit a new sensor buy the proper OEM one (Denso, NTK or Bosch notmally), don't fit cheap tat or you'll be worse off.

Really to diagnose it properly you need a tool capable of reading live data (fuel trim and O2 sensor voltage), but some garages will just throw a sensor at it and hope for the best.

I had a bike in 2 weeks back, "Lambda Probe Stuck Lean" was the diagnostic fault. I pulled the inlet manifold and gave it a "sniff" of brake cleaner, saw an instant reaction on the 02 sensor voltage. Turned out the Idle Air Control Valve was faulty, letting unmetered/ uncalculated air into the engine. O2 sensor was fine.

 

[Fab5Freddy]

It should be in Open Loop at Wide Open Throttle anyway, I suppose the Long Term Fuel Trims may be used as a modifier in the Open Loop fuel maps?.

What did the old plugs look like, black on the ends?.

If you do decide to fit a new sensor buy the proper OEM one (Denso, NTK or Bosch notmally), don't fit cheap tat or you'll be worse off.

Really to diagnose it properly you need a tool capable of reading live data (fuel trim and O2 sensor voltage), but some garages will just throw a sensor at it and hope for the best.

I had a bike in 2 weeks back, "Lambda Probe Stuck Lean" was the diagnostic fault. I pulled the inlet manifold and gave it a "sniff" of brake cleaner, saw an instant reaction on the 02 sensor voltage. Turned out the Idle Air Control Valve was faulty, letting unmetered/ uncalculated air into the engine. O2 sensor was fine.

The plugs were blackened at end yes, and neck of ceramic bit had black line around

I have made my mind up to find a good mechanic to look at it, because even if I had 'live data' OBD (and I just looked and you can put a bluetooth adaptor on the scart type end of mine and then send it to the iPhone app ) , I just don't really have the skills/knowledege confidence to do this without trial and error and possibly spend as much money chasing the fault , as I would in paying a mechanic. (when someone local recommends a good one)

 

[Mottie]

Plenty of people on the car forums highly recommend taking your car to a Bosch equipped diagnostic centre.

https://www.boschcarservice.com/gb/en/services/engine-service/engine-and-car-diagnostic-check/

 

[Fab5Freddy]

Plenty of people on the car forums highly recommend taking your car to a Bosch equipped diagnostic centre.

https://www.boschcarservice.com/gb/en/services/engine-service/engine-and-car-diagnostic-check/

Cheers Mottie - never heard of that service. Just looked and there's one local costs £84.
I'll go down and talk to them first, as ideally I'd explain what I am trying to achieve and then they would help narrow it down. If they just give me a 'read out' then I doubt I would be able to make sense of it or plan the next thing to do.

 

[Avocet]

I guess the only thing is that being a Yaris, it might not have Bosch engine management? Possibly Denso, perhaps?

 

[Avocet]

The plugs were blackened at end yes, and neck of ceramic bit had black line around

I have made my mind up to find a good mechanic to look at it, because even if I had 'live data' OBD (and I just looked and you can put a bluetooth adaptor on the scart type end of mine and then send it to the iPhone app ) , I just don't really have the skills/knowledege confidence to do this without trial and error and possibly spend as much money chasing the fault , as I would in paying a mechanic. (when someone local recommends a good one)

That's true, of course, but once you've bought the kit, you'll still have it for future use. I'm in much the same dilemma now, in fact. I've always maintained all our cars myself, but now my wife has bought a Skoda Kodiaq and the level of complexity is quite daunting! It is now out of warranty, so I don't mind taking it out of the Skoda dealer network (our local one was useless anyway), but I think I'm going to have to bite the bullet and invest in some "proper" diagnostic equipment. It won't pay for itself on the first job I do, but I expect there will be others. We normally keep our cars for a long time. Besides, I imagine it won't be long before you can't even top up your bloody screenwash without plugging them in to a diagnostic machine!

 

[Mottie]

Cheers Mottie - never heard of that service. Just looked and there's one local costs £84.
I'll go down and talk to them first, as ideally I'd explain what I am trying to achieve and then they would help narrow it down. If they just give me a 'read out' then I doubt I would be able to make sense of it or plan the next thing to do.

As far as I know, they are Bosch franchises in regular garages. They have to have the latest equipment and trained staff to maintain the franchise. I'm pretty sure they will diagnose and carry out a guaranteed repair too. Have heard very good things about them.

 

[Fab5Freddy]

Plenty of people on the car forums highly recommend taking your car to a Bosch equipped diagnostic centre.

https://www.boschcarservice.com/gb/en/services/engine-service/engine-and-car-diagnostic-check/

Ok, I went down to the Bosch centre, very helpful people . Had a good chat and explained my issue and what I was hoping to achieve by having diagnostic.
It would be £90 and basically give the range of things that may be at fault (or a specific one if that is the code), but for me they would then have to drill down into the data and continue work testing each sensor etc and that would be charged by the hour, bit they would be pretty sure they would then give me a definitive answer to what should be done.
I didn't ask the hourly rate but would be guessing £50 or so and I doubt you could do the extra work in under an hour.
So, I am now pondering on whether to do that, or just find a garage that I could trust and has the required knowledge/tech to get straight to the solution and fix it.

 

[Mottie]

I don't know where you are based but I don't think there would be many garages charging as little as £50 an hour.

 

[Fab5Freddy]

I don't know where you are based but I don't think there would be many garages charging as little as £50 an hour.

I'm a bit out of touch..

 

[Fab5Freddy]

I guess the only thing is that being a Yaris, it might not have Bosch engine management? Possibly Denso, perhaps?

Most of the parts in there are Denso, but not sure of that means the engine management system is too?

 

[Mottie]

I don't think the make of management system is relevant as most decent diagnostic equipment should just about cover every make.