EML

[The Other Stu]

Thanks. Yes had a look at the extenders they seem to be 18mm thread which hopefully is the same on the cat. Is there room for a straight one or would I need an angled one to fit?

I don't suppose there is a lot of point getting an expensive code reader

An £8 one does the trick for me   s:mrgreen: :mrgreen: s:mrgreen:  (Although you need to snip two of the pins off, because it makes the ABS light go nuts and my airbag light is half on)

[Ardent]

I don't suppose there is a lot of point getting an expensive code reader

Non at all.

[Jon_G]

If the emissions were tested and good, the cat is working.

If the primary/manifold/precat cat is still present (and functional) then the emission readings may still be pretty good, even if the main cat was operating below standard?

[chris goldson]

It's quite confusing the different views on the pre-cats and other issues.

I know members have said that doing the mods on the pre cats should not lead to EML problems but when I look on the sites advertising the main cat extenders they say they are a must in keeping the EML light off if the pre cats are missing or have been modified. If keep having problems might try one of these on the main cat to see if it does the trick.

[Jon_G]

It's quite confusing the different views on the pre-cats and other issues.

I know members have said that doing the mods on the pre cats should not lead to EML problems but when I look on the sites advertising the main cat extenders they say they are a must in keeping the EML light off if the pre cats are missing or have been modified. If keep having problems might try one of these on the main cat to see if it does the trick.

Do you still have your precats fitted? I have, but many do remove them... I don't believe that removing them should cause an EML problem UNLESS your main cat is defective.

I'm still not convinced about what your problem is.  Confirming what the fault code is would be useful (as would knowing if you still have the precats fitted).

At least fitting that spacer is one of the cheaper options.

[Carolyn]

I have two cars.  One with a Toyosport manifold and aftermarket cat and one with a de-catted stock manifold and stock cat.  Both have no EML light.  Both pass emsissions testing. Neither uses a spacer/extension on any sensor.  It looks most likely that it is a sensor problem.

[1979scotte]

I thought the only reason you fitted a spacer was if you had a sports cat fitted.
Pre cats do very little once main cat is up to temp.
I have no pre cats and a 200 CEL sports cat and have no issues with passing mot or eml.

[chris goldson]

Many thanks.

Still searching for a genuine Toyota Cat as might change that as well at same time

That might be expensive! If your emissions are ok, you might be better fitting one of these (this one is just an example, make sure you get one that fits!)...  m http://www.ebay.co.uk/itm/UNIVERSAL-EXH ... SwkZhWTcbz m

If you have an obd2 reader that can give real-time data then you should be able to tell if the post cat lambda sensor is working by assessing the variability of the output data. Maybe the problem is that sensor?

Hi Jon

Most of these look to be 50mm long, I have not had a look to see where the sensor fits but wonder if there is enough room to get one of these in although there are angled ones as well. Do you know if there is room to fit one pleasef

[Jon_G]

No idea, sorry. Never had to fit one!

[chris goldson]

Just spotted another cat on ebay which says Toyota 12209 Sango, does anyone know if this is a genuine Toyota cat and if it will fit my 2006 MR2. Anything worth a try to put the light out !!

Contact the seller and ask for the part number?

However, if the emissions are OK then it doesn't seem worth the expense and cost of replacing the cat. Either it is a poor post-cat lambda sensor OR the current cat is functional but inefficient, in which case an aporopriate sensor spacer may be a more cost-effective fix.

What code are you actually getting?

Jon

Just picked the car up again. All three sensors have been changed now to Denzo's and cat replaced during previous visit. The fault code which has been consistent throughout was P0420 cat below threshold bank1. Obviously not know for some time if this has now been resolved.

Best Wishes


Chris

[Jon_G]

Fingers crossed that this problem has now gone. I guess that'll mean it was the lower sensor.

[Ardent]

Hope it is sorted now.
Was the exhaust ssytem checked for gas leakage as this can also throw the P0420 code.

[chris goldson]

Yes they had to do a few welds around the pre cats, probably could do with a new/another  unit at some stage, but still going for the spacer if the dreadedd EML comes on again.

[Ardent]

Yes they had to do a few welds around the pre cats,

Could you elaborate on that.

[chris goldson]

Hi yes they had to do some welds around the tops of what they called the jam pots where there where some hairline cracks

[Ardent]

if you need a replacement. Bound to be one floating around on here as people swap them out.
Not heard of one needing welding before.

[1979scotte]

Welding of the stock cast manifold is news to me.

[chris goldson]

Its around where the four pipes from the manifold go into the two pre cats.

Don't know if there is a wanted section or parts for sale on here to find a replacement which would be ideal?

[Ardent]

 l viewforum.php?f=63 l

[chris goldson]

Hope it is sorted now.
Was the exhaust ssytem checked for gas leakage as this can also throw the P0420 code.

Guess what EML light on again - beyond belief !!

All three sensors changed and new cat but still same problem and same code. Now fitted spacer to see if that does the trick but patience now more than a little thin.

[Carolyn]

My money is still on an exhaust leak.  Hope I'm wrong and the spacer does the trick.
Do you have all the heat-shields on around the manifold?  I ask this as there is a simple way if tracking a leak down - but you need access.  A piece of coat-hanger wire, with some tissue taped to one end.  Pass it around all the places where it might leak, welds and joints.  You'll see it flutter when you get close.

[Newbie57]

I'm watching this with interest as I have exactly the same issue.

[Jon_G]

So you found a spacer... was it a 18mm thread like the eBay examples?

If this doesn't fix it, then it can sometimes be necessary to stuff wire wool into the spacer to further reduce sensor sensitivity.

Good luck with it, hope it'll stay OK.

[chris goldson]

Thanks Jon much appreciated. Yes it is 18mm thread

[ptennisnet]

I had P0420 and my emission results were pretty bad.  After a bit of internet research, I took the cat section of the exhaust off and flushed it with hot citric acid solution for 6 hours.  Unfortunately, I couldn't get the sensor out and bent it whilst trying.  I also noticed that there was probably still a leak where the pipes joined the flange for the manifold (I'd tried fixing this whilst it was on the car and couldn't feel a leak when it was running). I put fire cement all the way around the joint  (I don't know if it's cat-safe but I had it in the garage so thought I'd use it).

I don't know whether it was the flushing or there was a leak but the p0420 hasn't come back and my fuel economy has gone up.  Unfortunately I've created a P0141 heater circuit code from that sensor but research on here suggests the sensor is working and that there's a resistor fix for the heater circuit.