CO Problems

[Bolsom]

I live in France and my SE has just failed the emissions test. It was .3 at idle and .85 at fast idle which is too high. I think fast idle is about is about 3K revs.

About 7 years ago I had the engine management light coming on with code 13 = O2 sensor. This caused a protective rev limit of 4K revs.
Disconnecting the battery lost the stored faults and it would carry on OK for about 50 starts. I fitted an O2 sensor and the fault was cured. This was a general purpose one, not a Lotus made of gold one.

I have looked at the previous threads I could find on the subject. Does anyone know when the 9930 chip was introduced and where I might get one if needed? My adjustment pot is set 1/2 turn from lowest (ie. almost all the way to the left).
I suppose its possible that the O2 sensor is knackered. I have been a little
unwell for the last year so it has not been used. Is there an easy way to tell if this is so. I do not have any diagnostic aids.

Thanks for any advice

Colin

[Enright]

What are the target figures for your emissions test?

I am confused if you have both a CO potentiometer AND an O2 sensor on a SE. If your car has a standard chip, it will only use one OR the other, not both.

Usually if it is a SE then it should use the CO potentiometer, but the setting of the CO pot only affects the mixture at slow idle. At a certain point (I do not know what the revs are of this point) the ECU switches to a different map and ignores the CO pot setting. In a SE the O2 sensor is always ignored.

If it is a S2 then it should not even have a CO pot fitted. If it does, then it will be ignored. The O2 sensor monitors the air/fuel ratio throughout the rev range. The signal is passed to the ECU which adjusts the mixture to correct it. It's a pretty intelligent system.

The best things to start by checking are that your spark plugs are gapped correctly and that the timing is correct. Also the Coolant Temperature Sensor (CTS) and the Hall Effect Sensor in the Cam Angle Sensor (CAS) are far more common failures than an O2 sensor.

I would recommend downloading Elanscan, and buying an Elanscan lead. Then you can post a zip file on this site and there are a lot of people who could help you with the analysis of it.

GeoffSmith WAS making Elanscan cables, but I don't know if he still is. You should PM him to ask.

[GeoffSmith]

Neil's right. You can't have an O2 sensor and a CO pot. As they use common wiring into the ECU, they're liable to confuse the ECU as well.

As you say you've got an SE and a CO pot, I'd suspect you haven't got an O2 sensor. I'm guessing that you may have read a code 31 for a code 13. Code 31 is turbo overboost and will cut the fuel as you describe.

I would check your base timing first but suspect it may be your CTS reading cold which the ECU compensates by enriching the mixture.

I still do interfaces - check my website and take off the 20% LEC discount.

[Enright]

Neil's right. You can't have an O2 sensor and a CO pot. As they use common wiring into the ECU, they're liable to confuse the ECU as well.

Oh, you can HAVE one, but it just won't DO anything!
With my ESM V5 Switcher Module, so long as I turn the engine off before switching from SE to S2 mode (or back), I can leave everything in place and connected, and I don't get any fault codes.
It's just that if you're using one, then the input from the other will be ignored. It will just sit there looking pretty!

So just one other question Bolsom, when you say you got an O2 sensor, did you remove the bolt from the big hole in the Turbo heat shield and screw it in there, then connect it to the plug near the RHS headlamp motor?

[GeoffSmith]

My mistake, but I knew there was something which conflicted...... The CO pot is common to the EGR sensor input (EMJ.4-10) going into pin B12 on the ECU. Off topic I know, but interesting nontheless, did you plumb in EGR Neil, or has Alan given you a non-EGR closed loop PROM?

[Bolsom]

Yes I did screw the sensor into the manifold after removing the blanking plug and I did wire into the 3 pin near the RHS headlamp motor.

The car is in a local garage here in France at the moment with a guy recommended as good. I explained the problem and history in my pidgeon french. I don't hold out too much much hope. I expect the remedy will be to procure a 9930 chip, remove the O2 sensor, restore the original wiring and tune the O2 pot at said garage. As I put the sensor in 7 years or so ago I hope I can remember how the wiring went. At my age memory is a problem. I guess I need to contact Lotus at Hethel to obtain the chip.

Many thanks for the advice and comments. I will post if I get a result

Colin

[GeoffSmith]

Colin,

Did you fit a 1499 closed loop PROM when you fitted the O2 sensor? If you left a 9929 or 9930 PROM in, then the O2 sensor will not have been doing anything! Have a read of Neil's write up in the Wiki. If you need a replacement PROM, I'd recommend you get one off ESM - click on the "Mountain Chips" button at the top of the page.

[Bolsom]

Oh ye of little faith! (Me that is) .My friendly French garagiste fiddled with the car and took it to his friendy test garage and it passed the test by the skin of its teeth - If I understood his french/spanish correctly.

Looking at the Wiki page, a closed loop seems the answer to CO problems plus a little extra power. I am consiering the Killimanjaro chip
and Impulse sensor. Does anyone have a negative experience of this?
I want to sort the CO out and the extra power will be nice. The car has done 28K miles and I only use it for the road. I find I can cruise at 80+ and still get 34 MPG. As the extra power is only about 13 BHP I assume it will not have a big impact on consumption when driven steadily. (But not that steadily)

Thanks

Colin

[Bolsom]

Hi all,

I have looked at Rockauto and they have various O2 sensors. The Bosch part 13277 @ 86.79 dollars seems to be the safest bet. Has anyone experience of using this with the kilimanjaro chip?. I also see 2 prices on the Mountain catalogue. Is this exchange and straight purchase and can the exchanged chip be whatever is fitted to my SE?

Thanks

Colin

[rip]

Colin,
I have also been looking into both a chip upgrade & O2 sensor for my SE recently so have done some research on this (all from LEC )

O2 sensor should make your engine run more efficiently while the turbo is not providing any boost (ie driving at a steady speed).
A Kilimanjaro/Everest chip changes boost conditions and should have no effect on economy while you are driving at a steady speed.

A replacement mountain chip costs just under £100. ESM sells them for all variations of PROM. A switcher costs £180.

You will need a like for like replacement (ie 9930 Kili for 9930 stock). If you want to add the O2 sensor to 'close the loop', you will need to exchange it for a 1499.
On the CO Pot thread, Enright came up with a very good suggestion:
If you get a switcher, you can split the mappings between 9929/9930 & 1499, although you will have to specify this when ordering it. This will give you an easy upgrade path (add your O2 sensor & activate it by simply switching to a 1499 mapping) and will allow you to easily switch back to open loop if you have any problems.
Enright also suggests that the cheaper Bosch O2 sensor is sufficient & he converted his SE to closed-loop early last year.

If you can run Elanscan (like suggested earlier), this will tell you what PROM you have.

[John_W]

... I also see 2 prices on the Mountain catalogue. Is this exchange and straight purchase and can the exchanged chip be whatever is fitted to my SE?
Thanks
Colin

Colin,
The Mountain chip itself is just a chip (with very special knowledge and testing having gone into defining its properties). As such it is not too expensive to swap, hence the low "exchange" cost.

However, it is mounted on a Moates adapter "daughterboard" thing which plugs into the Elan ECU in place of your original Lotus chip setup. This Moates adapter costs quite a bit and has to be imported from the USA. Once the Moates adapter is fitted to your ECU you can fit any Mountain chip you want (except the V5 switcher thing, which uses an even more costly interface).

Thus once you've bought your first Mountain chip, you already have the Moates adapter. Changing/swapping/upgrading the chips thereafter only involves changing the chip itself.

Your original Lotus chip and mounting is of no use except to keep in case you want to replace it before selling the car. As such, it has no exchange value.

John