Engine Management Light Still On

[Tycoon]

Hey guys, I've read through most of the threads regarding the engine management light coming on after the precats have been removed, but couldn't find anything regarding my situation.

So here's how it stands:
After suffering from precat failure, I had the motor redone to fix the oval bore so I no longer use excessive oil.
Replaced both 02 Sensors at the top(manifold)
Had the precats, or what was left of it removed

The car driving fine with no management light on but when I had to remove the main cat as it was blocked, the management light came on a few km's after.

What to do now?

[Wabbitkilla]

If you plug in an OBDii reader you will probably find something line P0420, Catalyst operating below threshold.
If you have removed the main cat, the 3rd O2 sensor will detect there's no catalyst and throw up the engine light.

[Tycoon]

What can I do/add in order to overcome this problem with the light staying on all the time?

[Wabbitkilla]

First find out what code it's actually reporting and then deal with the cause.

[Tycoon]

100%

Thanks for your help.

[Wabbitkilla]

IF it is P0420 then you have a couple of choices, simplest is to fit a spacer  like these, or fit an electronic gizmo that mimics the signal.

[Anonymous]

I had to remove the main cat as it was blocked

Could you just clarify that there is/is not a cat on the car?

[Tycoon]

There is no cat on the car.

[Steve Green]

Can you confirm the code?

[dcod]

If you have no cat then I would expect you to get a P0420.

The ECU compares the waveform read by the O2 sensor before the cat with the waveform read by the O2 sensor after the cat. I think the ECU varies the air/fuel mixture from rich to lean to create this waveform. The ECU expects the waveform, post cat, to be a lower frequency (switches between rich and lean much slower). If the waveforms are the same then a P0420 is created. The code is generated after a few journeys at specific revs.

I have no idea how to fool the ECU. I would weld in a sport cat.

[Anonymous]

If you have no cat then I would expect you to get a P0420.

The ECU compares the waveform read by the O2 sensor before the cat with the waveform read by the O2 sensor after the cat. I think the ECU varies the air/fuel mixture from rich to lean to create this waveform. The ECU expects the waveform, post cat, to be a lower frequency (switches between rich and lean much slower). If the waveforms are the same then a P0420 is created. The code is generated after a few journeys at specific revs.

I have no idea how to fool the ECU. I would weld in a sport cat.

Or standard cat about £150,  m http://www.cats2u.co.uk/advanced_search ... trol%20Cat m

Or risk a used cat from a breaker.

[dcod]

I got a cat from cats2u, didn't fit (maybe 'cause I have a 2zz) but my mechanic said it was very cheap and shoddy.

[Wabbitkilla]

Maybe you didn't spot the OP is in Soth Africa?   s:wink: :wink: s:wink:  

I think you have the answers here, always best to check the codes and confirm before spending any more money   s:D s:D

[Tycoon]

I've chatted to a few guys & they seem to think a cat fooler would do the trick.

[Tycoon]

Do you guys have your own diagnostic software to check for the codes yourselves?

[dcod]

Do you guys have your own diagnostic software to check for the codes yourselves?

Indeed :



Pretty cheap off ebay.

Never heard of a cat fowler.

[Jon_G]

Certainly not heard of a cat fowler either - see spacer, as mentioned a while ago

[Tycoon]

My apologies, South Africa they refer to it as a cat fooler.

[uktotty]

So after 20 posts saying what's the code, what is the code??

[Wabbitkilla]

You can't fool a cat


But, anti-fowlers like in the ebay link I pointed to can help, or there are little electronic gizmos designed to fool the ecu into thinking there is a catalytic converter working, E (Ian) has one on his car.

But you really need to know what the code is to know you're doing the right thing.

[Tycoon]

Since I don't have my own OBDii reader yet, I'll have to get to a workshop that can check for me.
Will let you all know as soon as I do.

[uktotty]

Just bear in mind you can buy an obd for 200r and a garage will charge you 400r to read the code mate

[E]

Sorry mods about the link but hoping this is of use, this is the sort of thing I'm using not necessarily from this vendor but Ive been cat free for over 3 years with no codes.
 m http://www.ebay.co.uk/itm/Universal-Oxy ... 3379dba417 m

[Wabbitkilla]

Thanks Ian, that's fine as it's in response to a query.

This is quite an interesting article on the simulators, bear in mind that many of them don't have a resistor sufficiently robust enough to mimic the heater circuit though!
 m http://reviews.ebay.com/Truth-about-O2- ... 0002812356 m

[E]

Actually your right Nik now you mention it. I bought the same unit as this but without the heater element and then fitted a resister to take care of the heater element side. another link to when i did mine.

 l viewtopic.php?f=7&t=25880 l