Silly high emissions!
Hi folks,
I have just had an emissions reading done as I need this to register the car in Spain shortly.
This iO is a U.A.E. car from new and therefore came without a catalyst or Llambda sensor. It does have a MAF and I assume (not checked this yet) it also has a map sensor. Plugs, air filter and oil are nearly new.
Anyone have any bright ideas as to why the readings are so high and how I might be able to reduce them?
Thanks, Guy
Kind of a result??
Thanks for the reply Fordem........if not a little terrifying after what I have spent on this car! 
Some time last year I discovered the flexi section in the down pipe was leaking so I decided to replace it, remove the box after it and fit a cat so the exhaust would resemble an EU car and hopefully improve the emissions. Well after studying those horrendous figures from the emissions test the other day I thought "maybe the cat is causing a restriction" so decided to take the cat off and smash out the honey comb. Well I sort of had a result yesterday morning with another emissions test.
I know it has still failed but the figures are SO much better than with the cat fitted. MOT tester said it was one of the cleanest running "non cat" cars he has ever tested! Fingers crossed the Spanish will accept it!!
Are you sure it has no lambda sensor?
Are you sure there is no lambda sensor - I've never heard of a car with a catalytic converter that didn't also have a lambda sensor.
I'd say that engine is still on the cool side - 60*C oil temps - do you have any idea what the coolant temp was?
As I mentioned previously, without a lambda O2 sensor, the ECU will fuel the engine based on a pre-programmed algorithm (or curve) - if the engine is cool (or the ECU thinks it's cool) the ECU will richen the mixture up in pretty much the same way that the choke did on the older carburetted vehicles.
Have you just dscovered the reason it was never registered and perhaps abandoned, it's just too much of a headache to make it compliant?
It never had a cat or lambda
It never had a cat or lambda from new. I installed a cat hoping it may improve the emissions but it did the opposite! Engine was hot enough - I had been driving it around for at least 25mins before both tests.
This is what it looks like -
This is a diagram of a car with a cat -
Just to add.......
Just to add, the down pipe has no lambda either and is about 2-3 cm longer than a down pipe from a cat fitted car. I found this out as I decided to replace this down pipe due to the flexi section leaking. I had assumed the down pipes would all be the same but they are not. This meant that the box after the down pipe would not mate well so I decided to buy the cat as the system would then all fit and I assumed the emissions would be better!
Here is a picture I have of the original system.
As you can see there is no lambda (oxygen sensor).
Syndicate
You may not be able to register that car...
A "non-OBD2" vehicle just will not pass OBD2 pollution testing.
If you have to pass smog to register you may not be able to register the vehicle - without a lambda sensor the engine runs open loop, the fuelling (and tail pipe emissions) will be dictated by a fixed algorithm programmed into the ECU. Without a catalytic converter, the CO readings are going to be higher because the converter "burns" the CO, converting it into CO2.
You've already replaced plugs, airfilter, etc., make sure the engine is up to operating temperature (and make sure the ECT sensor is good - by ECT, I mean the engine coolant temperature sensor that feeds the ECU, it is NOT the same sensor that drives the dashboard temperature gauge. Anything that allows the engine to run more efficiently should reduce the CO emissions, but I believe you'd be better off looking for loopholes that allow registration without smog testing.