Engine Fault Light + Misfiring Avensis D-4 Auto

[B3rtie]

Hi there.

I have been having one or two problems with an Avensis. The car is a 2002 2.0 VVT-i GLS Petrol Auto and hase done around 90,000 miles

The problem is

1. mis-firing,

2. appearance of an engine fault code (the code is P0430 also discussed elsewhere in the forum) and also

3. A very low tickover around 550rpm.

Now I note that a number of you advise that this is due to a fault on the Cat'. This is the route I have taken. Work carried out is:

1. Full set of new exhaust and cat sensors (5x I think)

2. ECU software update

Mr T advised that the problem was most likely to be the cat' which would have to be replace and ECU updated, but an engine remap may improve tickover and stop the P4020 and P0430 codes appearing at first. The remapping/software update didnt improve matters. The new sensors seemed to cure the problem of the code coming back until recently when the P4030 appeared again but this time on its own. This was reset by my local garage, but the engine warning light has come on yet again. I havent had this checked yet as I intend to buy/borrow a OBD2 reader.

The real question I have is that imediately before the light came on the car would misfire (otherwise running like a rocket) on steady cruising speed or backing off the throttle after driving at constant speed on the motorway for example. the misfire seems to be throttle position and engine speed related - seems to be worse around 60mph or 2500 rpm. accelleration is also poor in this area.

This leaves me thinking... ...

1. Why is the car running poorly at times and?;

2. Is this related to the possible Cat' working below "threshold" (the cat has not been replaced yet as the £500 replacement cost is putting me off. My independant local garage is still saying that they dont think it is the cat' since the MOT CO readings were so good.

Does anyone here have any ideas as to what it could be and possible items that could be checked?

What does below "Threshold" mean given that it is doing its job of cleaning exhaust gas to MOT standard?

Any advice would be much appreciated especially if it saves my wallet from being unduely emptied

Thank you for reading

[cmia]

2500 rpm

is that any gear ?

[B3rtie]

2500 rpm

is that any gear ?

Hi, Thanks for replying yes in any gear, only just noticable when accellerating (sort of a flatspot).

[cmia]

Ok it looks like mr T is pulling a fast one.

put this error code into google follwed by toyota and read.

P0430 is to do with the cat.

Now the reflashing of the ecu basically loosens the parameters of the c02 readings etc.

I would suggest you look at the actually oxgen sensors in and around the cat.

[B3rtie]

I ran a search with the details and a lot to get through! Surprising how much really - will post results.

[silverarrow]

:D need new cat long known problem with cat ecu and feedbak loop software and upgraded ecu is needed not just a new cat the ecu needs a remap and different chip

a remap alone will not fix this problem the cat needs the new ecu and new software.

use petrol injector and cat clean as well.

error code is not just on toyotas

[B3rtie]

need new cat long known problem with cat ecu and feedbak loop software and upgraded ecu is needed not just a new cat the ecu needs a remap and different chip

a remap alone will not fix this problem the cat needs the new ecu and new software.

use petrol injector and cat clean as well.

error code is not just on toyotas

so what you are saying (again - have seen your previous posts) is....

1. new cat'

2. new ecu

3. full setup i.e. ecu reprogram because it comes with the old software on it.

If correct, why hasnt Toyota been strung up big time about this about this?

(Think I will buy a Renault next, no, in fact I will)