[TuttiFarutti]

Hi! This Oscar from Barcelona. I just registered in this forum cause im going crazy with some sensor problems and im unable to find solutions here in Spain.
As i had the MIL light up in the panel i went to a shop and some error codes appereared indicating that some oxygen sensors should be replaced. After i was very clear with the guy telling him “please get the OEM references” he decided to install Bosch sensors. The light came up again🤬
After that he said now the error code was from upper sensors so i decided to replace them by myself. I got some Denso sensors DOX-0246 and DOX-0242. I went back to the shop, the guy made a reset and after short time boooom surprise light again.

ive been reading post here but i decided to register say hello to all community and hoping for slme specific help

thanks in advance

 

[Bigphil555]

Welcome to the forum, and sorry to hear of your troubles.

As you have replaced both sensors with good quality OEM/OE parts (and well done with that, a very good move), the trouble is somewhere else.

Do you have the original codes that were set? This may give us some direction to help you. The problem we have at the moment, is that it could be one of many things. Yes it could have been the sensor or heater, but it could be a circuit code. It could be lean or rich codes, could be a misfire/mis fuel - the list goes on.

As the light is on, may I suggest you buy an OBD2 reader - one that can read codes, but also show some live data - we can probably help then. A reader around 50 euros will probably do the trick. If you get the codes, please let us know, and we can help.

 

[TuttiFarutti]

Thanks a lot Bigphill! I set an appointment in another shop for monday, but i will also get an OBD2 as you recommended. Will give you guys feedback. I apreciate your answer.

 

[TuttiFarutti]

Good morning! I already ordered an OBD2 reader. The Autel Autolink AL319. Let's see how it works. Very good revieuws.

Giving feedback in a couple days!. Have a nice week all.

 

[Bigphil555]

Look forward to seeing the results

 

[TuttiFarutti]

Hi again! Im back with some codes. By the way, the autel works amazing.
Error codes:

P0420
Catalyst System
Efficiency below threshol
Bank 1

P0430
Catalyst System
Efficiency below threshol
Bank 2

New sensors that the shop installed:

bosch 1 st/pc
LS 31687
0 258 986 687
-760

(both of them are the same sensor)

im not a pro guy but for some reason i think the problem is with new sensors.
Thanks in advance

 

[Bigphil555]

Those codes most certainly help, but what ever you do, until we have worked out the exact problem, hold fire on the parts canon (cats are not cheap!!!!!)

Can you get hold of live data from your scanner - I will try to look too. I would need to see the upstream and downstream O2 readings when the car is in fuel control (closed loop).

Can you also post short term fuel trim and long term fuel trim for both banks at idle (700 rpm), and 2500 rpm please - this will be a good start

 

[Bigphil555]

In your scanner it is called live PCM datastream

 

[TuttiFarutti]

Thanks for help. I apreciate it. Doing it asap

 

[TuttiFarutti]

Well i think the figures were in range (i think) i tested in the autel, pressed all the butons and saw live data. Sensors were around 1,000

 

[TuttiFarutti]

Live data 700 rpm:

 

[TuttiFarutti]

Live data 2500 rpm:

 

[Bigphil555]

Some good data from your scan tool, and thank you for posting those images.

At idle, both of your air fuel ratios at around 3.2V means the ECU is in good control. You are running rich slightly, as the ECU is removing circa 7.0%. At 2500rpm, this reduces to circa 3% being removed.

Both of the rear sensors are at 0.64 to 0.74 - again slightly rich but not really a problem. So, if they are genuine Bosch, they are alive and talking as best I can tell.

One to note from the figures is that your MAF seems to be reading low - suggest you use the proper MAF cleaner and give the wire a decent spritz. If you look at the wire (do not touch it) does it look dull and dirty, or shiney? it needs to be clean.

If the ECU is thinking under on the air flow it will remove fuel.

Also, over a 2 minute period, again in fuel control, can you tell me the maximum and minimum readings of both sensor 2's please.

I am going to be partially offline over the next week, so it may take a little time for me to answer - I will get there tho

 

[TuttiFarutti]

Some good data from your scan tool, and thank you for posting those images.

At idle, both of your air fuel ratios at around 3.2V means the ECU is in good control. You are running rich slightly, as the ECU is removing circa 7.0%. At 2500rpm, this reduces to circa 3% being removed.

Both of the rear sensors are at 0.64 to 0.74 - again slightly rich but not really a problem. So, if they are genuine Bosch, they are alive and talking as best I can tell.

One to note from the figures is that your MAF seems to be reading low - suggest you use the proper MAF cleaner and give the wire a decent spritz. If you look at the wire (do not touch it) does it look dull and dirty, or shiney? it needs to be clean.

If the ECU is thinking under on the air flow it will remove fuel.

Also, over a 2 minute period, again in fuel control, can you tell me the maximum and minimum readings of both sensor 2's please.

I am going to be partially offline over the next week, so it may take a little time for me to answer - I will get there tho

Thanks a lot Bigphil!!😍 No worries about answering buddy…. Im very thankful even if it takes you 2 weeks.
Theres a part that i dont understand… maybe because language:

“Also, over a 2 minute period, again in fuel control, can you tell me the maximum and minimum readings of both sensor 2's please.”

what does “fuel control” and “closed loop” means??? I will try to send what you are asking me.

Also i read in the forum about MAF and im ordering today the cleaner.

 

[TuttiFarutti]

 

[Bigphil555]

Apologies for using the strange terms, let me try another way

On your scanner, start the engine. The scanner has data called fuelsys A and B. In OL (open loop) the ECU is using default settings to warm up the engine. For full control, the ECU needs to be in fuel control and this is called closed loop (CL) - one of you pictures shows this.

What I am looking for is to see if the down stream sensors are alive and talking to the ECU when the car is in closed loop. When fuelsys says CL can you look at the voltage reading of both sensor 2's over say a 2 minute time scale. If they are reasonably stable, then your cats are good. If they are oscillating, potentially your cats are not doing their job.

After 2 minutes, can you very briefly rev the engine to 5000rpm (less than a second), and then return to idle. Can you tell me if the voltages on the rear sensors vary between 0.1v and 0.9v? This will determine of the sensors are working ok, and are not lazy.

Hope this is better for you my friend. If not, no worries, happy to keep explaining for you

 

[Bigphil555]

Just looked at your introduction, and it is a sweet looking Rav.

Could you look at the exhaust please. As you have both bank 1 and bank 2 on your 2.0 engine, you have one of the special engines that have 4 sensors (2 upstream and 2 downstream) - please could you confirm there are 4 O2 sensors (and not 2) - it is just to ensure we are looking at the right specs and wiring diagrams

 

[TuttiFarutti]

Just looked at your introduction, and it is a sweet looking Rav.

Could you look at the exhaust please. As you have both bank 1 and bank 2 on your 2.0 engine, you have one of the special engines that have 4 sensors (2 upstream and 2 downstream) - please could you confirm there are 4 O2 sensors (and not 2) - it is just to ensure we are looking at the right specs and wiring diagrams

It has 4, 2 before Cat and 2 after Cat. no needed to check again. 100% sure.

Thanks Bigphil for the help, the explanation and for the compliments.

I will also also check soon what you posted before. Your help is priceless.

 

[Bigphil555]

You are lucky my friend to have that engine in there - well worth looking after and getting back up to specification.

As we are (at the present) dealing with rich running (ie too much fuel or not enough metered air), can you look at the engine air filter too - if it is dirty/dusty it will need replacing too.

We need to give this engine the best chance we can to run sweet

 

[Bigphil555]

Just to check, with the service items you have replaced (and well done on going for the maintenance) did you use OE/OEM parts - our Ravs are fussy and can not cope with copy parts. Again, just a check BTW