Cat convertor error code

[tall_tog]

I'm just outside Perth Scotland 

I've ordered one of the readers Mr B suggested to clear code.

theres a local subaru independent near me and he's reset it twice when I got front wheel bearing fixed and again the next day when the light came on.

he's of same opinion that next step is the rear sensor then cat being the cause 

[tall_tog]

Ok update 

sensor changed , see pic of old one , and code cleared ,

p0420 but it says bank 1 after it , what does that mean ?

wait for 100 miles and I'll update !!

[Mark D]

If you had a sensor on the left half and right half of the engine then they would be bank 1 and bank 2

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[tall_tog]

Nothing positive to report sadly 

25 miles and lights back on , same code 

fed up pouring money down a black hole with this 

guess it now means it's definitely the cat ?

[Greenmamba]

Hoping I can contribute a bit, I picked up the following from another site I follow (tribute to Cardoc). Whether any of it works for you, no idea but there you are. Make of it what you will.

This code simply means that somewhere in the chain of events that controls the overall performance of the engine there is a problem and you have to find it.

List of possibilities:

Fuel quality (low quality fuel a/k/a no-name petrol)
Fuel quantity (filter or pump issue)
ignition issues (plugs, wires, coils injector flow)
temperature control (too high or too low)
vacuum leaks
exhaust leaks (not only an annoying noise, but it effects proper value reporting to the ECM by the AF and O2 sensors)
poor amperage conductivity (i.e. Battery or cabling)

Sensor issues can be:

MAF (Mass Air Flow Meter)
MAP (Manifold Absolute Pressure)
ECT (Engine Coolant Temperature)
AF (Air/Fuel ratio a.k.a. Front O2 which can be a single bank 1 for 4 cyl)
O2 (This is the actual O2 behind the CAT that lets the computer know how the CAT is functioning)

 

Good luck anyway!!

[Mr B]

Is a common code and sometimes as in your instance a pita resolve .
Is worth checking plugs etc, ideally want a road test with wideband logging & cats looking at , you can add a spacer fitting to rear sensor that moves tip out of main flow as a poor mans fix/function test .

[tall_tog]

Slight progress with no obvious cause !

light kept coming on (3 times since changing rear sensor)

last time yesterday was just as i was heading for petrol .

full tank of Sainsbury , reset code and would you believe 550 miles of cruise control !

filled with Morrisons petrol today - 100 miles later light back on.

sure is a mystery 

[Mark D]

It didn't come on the first drive after reset for me, always second drive or more.

Stick with Shell, either unleaded or vpower should be alright

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[tall_tog]

Been doing lots of miles since changed sensors 

still getting fault so have now run 3 tanks of vmax & bp ultimate through it.

what I have noticed is if I am motorway drivIng using cruise all seems ok unless I have to cancel cruise because of slower traffic at a hill. If I put my foot down once able to speed up it seems to trip the fault.

if I gradually build up speed then it's ok. Noticed it in A roads too, no cruise but get to a hill in 5th , put foot down and on comes the light.

might be my imagination but I've obviously been paying attention to driving conditions driving style .

this morning it came on after 66 miles of cross Yorkshire dales driving then stayed off for 250 motorway until I got to a hill on A9 and hit slow traffic going up hill.

does this make sense or indicate anything to anyone ?

thanks 

[Greenmamba]

The wheel bearing you had replaced could be one problem. The bearings have a tone ring which communicates with the sensor mounted on the hub and measures rotations etc, used in cruise control etc. If a bearing used doesn't send readable signals this could trip codes and disable cruise.

[tall_tog]

Another update 

been using Shell vmax or bp ultimate for couple of weeks 

getting worse , engine warning light now coming on every 50 miles 

cruise seems to be red herring as I've not used it to see what difference there was

giessing it's now time to look at changing the CAT

bit what if it still does it ??

[Mr B]

what are spark plugs like, do they show good mixture burn and in good order.

tricky one diagnose without logging oem sensors and physically looking at cat condition etc .
Can you fit cat yourself so cost minimal .

 

 

[tall_tog]

Haven't checked plugs if I'm honest , I'll get on to that , I forgot 

yeh I could fit cat , have looked at eBay but no 2005 ,  any advice on supplier pls?

thanks 

[Mark D]

I had ordered some exhaust bits from eBay.com instead of eBay.co.uk, maybe you could search on there if you don't mind waiting for one from the US

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[tall_tog]

Final update on this as about to post the next problem!

pluhs changed , no change , cel still coming on , sometimes 40 miles sometimes 200 miles 

cat it must be then 

[Mark D]

If you are planning on getting a cat, eurocarparts have their black Friday weekend deals going, looks like it ends Monday night. Order online, put in the voucher code and pick up in the store.

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[Mark D]

That's for a 2001 legacy, although didn't find it when clicking exhaust parts, there is a separate category for cat converters

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[Mark D]

Any progress?

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[Mark D]

https://vimeo.com/194371084

If you could see voltages from your exhaust sensors, this is what mine looks like after a new aftermarket cat and sensors, although I think one of the heater wires is loose.

It goes as high as .750 sometimes

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