Advice On Lambda Sensor After Garage Visit - Long Drive?

[GarethWilliams]

Sorry to ask so many questions!

My engine management light was on and it was diagnosed by a friend of the man I bought it off as bank 1 sensor 1 Lambda sensor when he plugged his box into the car. Yesterday the car went into a garage to have a new sensor fitted and when I came to collect it they said it didn't need it so didn't bother fitting a new one. They said even with the engine management light on the emissions were slap bang on what they should be so it wasn't running rich or lean and the sensor was working as it should.

For the life of me I can't remember his exact words but it was along the lines of saying the cat was a bit smelly and it was fooling the sensor. After knocking the light off his advice was to add an additive to the fuel and take it for a long drive as there was nothing wrong with it.

Well that was yesterday and today the light came back on. As luck would have it my £3 ODB2 bluetooth box arrived also today so after syncing it with my phone and using the free Torque app I knocked the light off myself (weirdly when I searched for logged faults on the app it didn't find any, even with the engine management light on?)

I plan on taking it for a good drive tomorrow so my question is, will any fuel additive do or is there a better one to use? Also, I'll be hitting the motorway so should I go 5th gear and drop the revs or keep it in forth with higher revs? Also, how long is a good drive? How long or far should I drive it along the motorway for?

[ents]

Hi

I`ve had similar problems (i have the same engine) and hitting the motorway does help a little if you mostly drive around the city. What really helps is then driving try not to change gear before 4000 rpm and accel. hard. Drive around like a maniac for a couple of weeks and see if it helps.

[GarethWilliams]

Thanks Henri! I'll be doing this today!

[GarethWilliams]

Ok! So reset the EML last night and drove the car today down the motorway in 4th so at around 65-70mph it was around the 4000rpm. From the home to motorway to location it was about 30 miles. Got there and no light on all the way so thought bingo but we returned to the motorway to go somewhere else and at 70mph in 4th once more it came back on. Stopped the car at destination no.2 and plugged the ODB reader in and it came back with error code PO420 which from Googling comes back as CAT efficency below threshold B1. So again I knocked it off and it drove all the way back home and no light came back on. I'm guessing it'll be back on again soon so now my question is, do I need a new catalytic converter or can it be cleaned? I've seen something on the market called something like cataclean that's supposed to work?

Apparently the lambda reading is good, as is the emissions so when the garage said the cat smelt maybe that was a clue that what is broke? I've got RAC parts and garage cover so maybe I should see if they cover it?

[ents]

Exactly like mine, i also have that exact code, every time the car warms up. Do you also have oil consumption? If not, you should be able to clean it with high revs and maybe adding some cataclean (if they even work). Mine consumes oil, so i didn`t bother to clean the CAT, burning oil makes everything inside the exhaust grimy, but i`ve passed the emissions every time (barely).

This fault comes present then the after CAT lambda sensor detects that the emissions are not perfect. So if your emissions are good, don`t change the CAT, just clear the fault codes and for the best, i have done this last four years. :( :(

[GarethWilliams]

Hmm, I don't think it burns oil, clocked nearly 1000 miles in it and never seen blue smoke and the oil light hasn't come on? Maybe I'd better check tomorrow?! So for me I'll get some cataclean on payday and bomb it down the motorway again and see what hapoens. I did see a YouTube video with a man who said to take it off and soak it in detergent overnight to de-smeg it?

[GarethWilliams]

Hi, just to re-ask. Do peoples oil lights come on then if its burning oil and getting low as mine seems fine. I've clocked nearly 1000 miles, no oil light on, car engine sounds the same, no oil smells from the exhaust etc? I know the real test is pulling the dipstick but as I didn't check it when I bought it then I don't have anything to go by.

After clearing the PO420 code on Sunday it drove back home down the motorway without coming on, I went to work and back on Monday (local, car stays cold as it's pretty close) and all was good but as soon as I drove it a bit further and it came up to the right temperature the EML cam back on!

So I'm getting the feeling that its either a case of living with it or just getting shot. Before doing anything drastic I looked into the whole oil burning thing and found that it wasn't an official recall but if you had a full service and it was under an age threshold they would repair it by changing the piston rings to rectify the problem? I'm wondering if mine has had this treatment and isn't an oil burner so I thought about checking the safety recall part of the Toyota site and it said:

We have identified that your Toyota is subject to a voluntary customer service campaign or outstanding safety recall.

So I'm thinking if maybe that is the above? I'll call them tomorrow to find out. If it doesn't burn oil and worst case scenario is a new cat and lambda sensor to put it right long term then I'll be down for that as I do really really like this car but, if my exhaust is smegged up in oil then there is no point spending the money as it'll never fix the issue and it'll be wasted money as before you know it the cat and sensor will be covered in oil and turn the light back on?

[ents]

Avensis 1.8 do not have oil level warning, so the light comes on then oil pressure is low. You must monitor the oil level with dipstick, try to do it lets say once a week in the morning, before you start the car and same parking space would be perfect and most accurate. Then you see oil level going down, top it up.

But if your car isn`t an oil burner, you could change the CAT but they are expensive, 400-600£. As long as the emissions are good, it will be cheaper to clear the EML every time it comes on.