P0420 Code

[xEla]

Hi everyone,

i have P0420 error code from my ECU...

i had it once about 1.5 months ago, it was just cleared then - nothing been done.

and last night it popped again... (i only guess it's the same one - haven’t diagnosed it yet)

i normally use Shell Super Unleaded or Texaco 97 petrol.

first time it occurred when after a while running on Texaco 95 (was short of money) i changed it to Shell Super again

and yesterday i had about half of a tank of Shell Super and topped it up with Total 97 (i was on the long journey from Wales to London)

all i'm saying that this problem with the sensor might be caused by different fuel types....

i also noticed that after engine light came on the dashboard - petrol started disappearing fast..

have read this topic -

http://toyotaownersclub.com/forums/index.p...71&hl=P0420

so the questions are - can i only change back sensor?

is there a cheaper alternative to Toyota sensors yet?

thanks

[GTForbes]

i'd change both sensors unless the diagnostic can tell you which one is faulty, i've only read the first few posts in that thread you have lined too and it seems you can use a universal 4 wire sensor so long as you modify it, this would be alot cheaper than getting an OE sensor.

the fuel consumption will increase while there is a fault withthe oxygen sensor as the ECU will go into a safe mode which unfortunately means ading alot of extra fuel, if this is left unresolved for too long then you could end up requiring a new cat

[xEla]

GTForbes

thanks for replaying,

but as you say - you only read first few posts - at the end the guy say that sensor didn't work for him, cos he needed changing air intake resistor, but that caused more ECU faults, hence was my question about any alternatives yet.

the actual code does more pointing to the back sensor:

Catalyst System efficiency below threshold (bank 1)

- which really means that the gases coming out do not follow the standard.

unfortunately i had to drive few hours after the code came out... is there any way to check cat now?

[GIDDLEPIN]

Please don't spend a shedload of money on O2 sensors CLICKY as you can see the before cat is just as easy to replace

[xEla]

GIDDLEPIN

oh, very good - thanks!

so how is your celica running? any probs with the sensor since?

[GIDDLEPIN]

GIDDLEPIN

oh, very good - thanks!

so how is your celica running? any probs with the sensor since?

The Celica went quite a while ago but the CEL was never any more bother