Re: 2zz P420 - Lucky me :(

[Wabbitkilla]

caps post can't be correct in this instance or the 02 in the manifold would only be reading gasses from 2 cylinders

Unless that's the RISK they take, and therefore it's not unfeasible that overall fuelling could be innacurate and therefore you get the false alarm of the cat under-performing. Stands to reason that with a 2ZZ in place it would be best to put the single O2 sensor in the pipe after the collectors befor the cat.

[markiii]

caps post can't be correct in this instance or the 02 in the manifold would only be reading gasses from 2 cylinders

Unless that's the RISK they take, and therefore it's not unfeasible that overall fuelling could be innacurate and therefore you get the false alarm of the cat under-performing. Stands to reason that with a 2ZZ in place it would be best to put the single O2 sensor in the pipe after the collectors befor the cat.

well if it is I'd never buy a conversion from them.

way back when these were pioneered on SC they were done properly

[dcod]

Out of interest have you noticed when the MIL comes on (in terms of driving style etc..)?

Interesting to hear that you have a lot of popping/banging on overrun, could be a sign of things being a little too rich under certain conditions and 'flooding' the exhaust/CAT/o2 sensors with HCs that the sports CAT just can't deal with in time to avoid pre/post sensors seeing a similar change....

Hi Andy,

The code has only come on once so far. In the middle of a 20 minute drive starting with 10 minutes urban and the rest motorway (gunning it a little) which is when it came on.

A friend of mine has said my car smelled a little rich when I drove past him once.

When my car was installed, I think the MAF from the celica was used (which had been sitting around for 1-2 months). I've got to get a round to cleaning. It's not as easy to get to now, I've got to take the whole pipe and filter off.

[dcod]

Thanks Cap for your detailed post. I think I'll need to read that a couple of times. Great info.

[Cap]

dcod.

As you see I've been Collecting and testing for a While..  

As for the Exhaust Header..  the Sole Purpose for the Existence, is Ease of Install..  and to pass the First Blush test by the Gov ..  If all four Fuel Injectors are Clean, then the Fueling will be close.. and 'Close' is good enough ..  Except when it comes to Smog Stuff..  then it needs to be Closer..  

I agree that the O2 Sensor should to be Placed where it will Snif all Four Pipes..  But only for Smog Reasons..  as the O2 Sensor is there to Add in proper Fueling for the Cat Converter..  NOT FOR PERFORMANCE!!!..  ( 14.7 AFR for Smog  Vs 13.5 AFR for Performance )..  if the O2 Sensor was for Performance, then there would be One O2 Sensor Per Cylinder..  Like the Land Speed Record Cars do Now..

If you really still think the Left Side O2 Sensor is Working on your 2ZZ Swap Motor....  Pull the Plug on it, and See what Happens..  

Cap

[markiii]

some serious misinformation here

what is "commonly" done in the US to pass CAlI inspections is irelevant to what Rogue may or may not have done in the UK

even then only reading 2 cylinders with the 02 is just asking to blow your engine as you will have NO indication as to whether the other 2 cylinders are running rich or lean

[Cap]

How is it more Dangerous to to read Two Cylinders VS Four Cylinders..  

When you are reading a combined Gas Stream, the Reading you are getting is an Average of the Gasses.. So the O2 Sensor is not Accurately reading ANY of the Cylinders.

Is it More Dangerous to Not Accurately Read Two Cylinders, or Four?..  

My Information is Correct..  it's your Perception or Reality that is off..  

Please point out the Information that is Error..  

Cap

[markiii]

the error is your stating what happens by some unspecified installers in the US

nether you nor I nor dcod know how Rogue chose to install this one. Therefore your information is pure speculation with regards to dcods install

[markiii]

How is it more Dangerous to to read Two Cylinders VS Four Cylinders..  

When you are reading a combined Gas Stream, the Reading you are getting is an Average of the Gasses.. So the O2 Sensor is not Accurately reading ANY of the Cylinders.

Is it More Dangerous to Not Accurately Read Two Cylinders, or Four?..  


Cap

imho 2 is worse than 4

if your reading all of the cylinders your correcting each cylinder based on the mixed results of 4 cylinders as opposed to reading 2 cylinders where you aren't seeing teh gas flow from the other 2 cylinders at all, your not even averaging in that case its just a complete guess

[Cap]

I agree..  This is Speculation on my part. I have never meat any of the People Involved, and it's likely I never will..  

But if this picture as posted is of dcods Car, then it's using a Header that was first MFG in the States for the Reasons Mentioned..  And if dcods Car only has Three Total O2 Sensors, and the 'Third' O2 is Giving him a 420 Code, then it's Likely that the Third O2 Sensor is being used for the B1B2 Sensor. The Header Shown, has Two Sets of Two Cylinders, that have an O2 Sensor per Set.
The Celica ECU only has Inputs From O2 Sensors for the B1S1, and B1S2 Sensors. That is TWO inputs Possible.

I have Speculated that the After Cat Sensor is Hooked to the B1S2 Sensor Input as it Should be. This has Left 2, O2 Sensors that are Mounted in the Header, to be used as Possible Inputs for a Single Input in the B1S1 Position on the ECU.

I Speculate from my Past Dealings with Analogs O2 Sensors, that it's not possible to Sum the Signal from two Analogue O2 Sensors, and get useable Data. You can get Data, but it will only Show the Leanest Signal, not the Average ( Lean is Higher Voltage )

So I speculate that the 2ZZ Installed in dcods Car, by Rogue, using the 1ZZ Lookalike bolt in Header ,  is installed the Same way it's done in the States, and that is using the Right Side O2 Sensor. As if you follow the Wiring for the Right Side O2 Sensor up to the ECU for the Spyder, is input is B1S1. And for the Celica ECU, the B1S1 O2 Sensor is in the Same Location on the ECU Plugs.

I ASUME that Rogue did not re-pin the ECU Harness to use the Left Side O2 Sensor ( Pure Speculation on My Part ).  So my Speculation still is if you Pull the Left Side O2 Sensor Plug, the Car will behave the SAME..

The Proof is to Pull it and Try it.  

Cap

[markiii]

But if this picture as posted is of dcods Car, then it's using a Header that was first MFG in the States for the Reasons Mentioned..  
Cap

My manifold is from ebay with the Celica flange welded on ... as far as I remember.

except for the fact that he already stated above its NOT the 1zz lookalike header you refer to

[Wabbitkilla]

Oh bugger ... it's all speculation till dcod finds out how Rogue wired it so there's no point in getting wound up about it.
Either way P0420 is the cat under-performaing for any number of reason, most likely it's just cooling too much and bringing the light up for occassional drops.
Sports cats do have a habit of doing this due to their size, coping with it is what we're after really ... anti fouler, filter, or fit a PFC and get rid of it.

[Cap]

Actually this has brought up a good Point..  

If the 2ZZ Swap is running ONLY the Right side O2 Sensor, then it's < Likely> that the 420 MIGHT be Bogus, as the Fueling ECU is only Snifing two Cylinders, and the After Cat is Actually Sniffing the Combined of all Four.  Two are Sneeking in on the After Cat Read..  

So I Speculate that the Improper Fueling of the engine MIGHT be tripping the 420 ..  and 420 was the Origional Complaint.

So to take it further..  I Speculate that if the O2 Sensor Input for B1S1 is moved to where all Four Gas Flows can be Read, then the 420 MIGHT go away..  

Cap

[markiii]

so you agree sniffing 2 cylinders is worse than 4 then?  :-) :-) :-)

[Cap]

so you agree sniffing 2 cylinders is worse than 4 then?  :-) :-) :-)

I agree that sniffing two VS Four will have different outcoms..  

For SMOG Reasions, I said all the Cylinders must be Sniffed, then fueling will Cycle Above and Below the Magic 14.7 Mark..  and the Smog Kings are Happy..  This will do Nothing tyo reduce the Risk of a Lean Cylinder..  and the Damage that can Result..  

For Performance, I said One O2 Sensor per Cylinder is best..  as this is the Only Way to Eliminate the Lean Cylinder Risk..  But for Smog..  this is not desirable without some Software Tricks..

For Performance ..  anything other than One o2 Sensor per Cylinder is a Risk..

Cap

[dcod]

I'll try and give Rogue a call tomorrow (thursday) and find out how they have wired it up. Anything anyone wants to know in particular?

Play nice while I'm gone.

Oh, and the P420 came up again today. So I don't think the other was a one off.   s:( s:(

[Cap]

Any Update to the theories and postulations ?

Cap

[dcod]

Hi Cap,

Called Rogue on Thursday but the guy who does the wiring had just left for Anglesea (possible for a race meet) and the mechanic couldn't remember if the O2 sensors are spliced together or one is a dummy. They are going to call me back after the weekend.

Just pretty much emptied the high octane fuel from my tank on a smile enducing drive through the New Forest and have now filled up with regular unleaded. I've got to do the same journey tomorrow, to pick up my hung over wife after a night on the town in Bournemouth, and shall see if the code is highlighted again.

If I find that one O2 sensor is not wired up then I may swap them over and see if the 'spare' makes any difference.

[Cap]

Just pretty much emptied the high octane fuel from my tank on a smile enducing drive through the New Forest

I see you are using the 2 + 2ZZ in a use for which they were intended  ..   s:) s:)

Thanks for the Update..

Cap

[Ilogik]

It is indeed great fun on the twisties. I love lift, you can't help but smile when you hear the grumble kick in

[dcod]

It is indeed great fun on the twisties. I love lift, you can't help but smile when you hear the grumble kick in

I want to spend my life flitting in and out of lift ... in a tunnel  s:D s:D  

With my exhaust, I even had Porsches and Ferrari staring at me! Especially the idiots who spent £80,000+ on a car that isn't a convertible.

[dcod]

Hi,

SInce returning to regular unleaded, I've made two 45 minute motorway journeys and no P420. These journeys were type that would give me the code before without fail.

Solved? Maybe. Only time will tell.

Dave

[Anonymous]

Ive been watching this post with interest. Simple question from a simple bloke. How does the O2 sensor work?   s:?: :?: s:?:

[andywood]

 m http://en.wikipedia.org/wiki/Oxygen_sensor m

Andy

[dcod]

P420 back  s:( s:(

So I deduce that it wasn't the high octane fuel I put in. It may have something to do with my other thread and my oil burning.

Now going back into investigative mode.