The Irish Mitsubishi FTO Owners Club

by **karlf** » Tue Jul 07, 2009 4:42 pm

I was given some reasons for the emissions being high and I want to know if there is any truth to these suggestions. I have the retest next monday so want to sort it out before then.
I failed first test on high emmisions , figures are as follows:
Low Idle:
co 0.81, allowed 0.5

High Idle:
Lamda:0.892 allowed:0.97-1.03
CO: 3.83 allowed 0.3
HC 204 ppm allowed:200
I have been given a few reasons for this, the CAT (its fairly new), Lamda sensor (it was suggested because the figures are close to levels allowed this might be ok) or oxygen sensor could be gone. It was also suggested that because I have an after market air filter set up that this could be causing a problem. I was told it might not let enough air in. Is there any truth in this?
Another reason suggested was that although I had serviced the car pre-nct I had not changed the spark plugs as I hadn't got the right tool. I was told this could have caused an issue with fuel not being burned correctly or something to that effect anyway. Is there any truth in this?
I have since changed them and we noticed that the ones on the back 3 plugs were in fairly bad condition and were different to the ones on the front suggesting they weren't changed in ages.
I dont know what CO or HC mean or what affects them, and I dont know what a lamda sensor measures. Sorry for my ignorance but could anyone shed some light on what these are and any ideas as to what the problem might be?
I was told to change the spark plugs, clean the air filters (I have 2), throw in one of those emission reducing solutions and give it a good hard drive before the retest, cross my fingers and hope for the best. Having my doubts about the reliability of the above suggestions so if some one can confirm or deny whether these are true I would appreaciate it.

by **Kace** » Tue Jul 07, 2009 6:18 pm

I don't claim to know a whole lot about the technicalities but when I had this problem this was what my research found :

Steps to fix emissions :
Replace Lambda (O2) Sensor, if readings are 'off the scale' then this could be your issue - mine were and this one cured my problem with a cheap €20 unit off eBay
Replace Cat, you say it's new - are you sure. As I've said before I would say it's 15 years old. Not too many brand new CATs installed out there really
Replace Engine Coolant Temp Sensor - you can test this one first, but my readings from other FTO sites quoted this as a potential problem

In relation to your other comments :
Drive it very hard before test to have engine seriously warmed up - a must !!
Add the Redex etc. - I'm sure this doesn't hurt but I wouldn't rely on this for much
Have a cleaner air filter - haven't heard that this could impact emissions but I'm sure it wouldn't hurt
Aftermarket air filters - I don't believe that this should have any impact on your emissions, however given the issues you're having, why not just put the old one back on anyway - Mitsubishi obviously thought that this was the best setup
Have good condition spark plugs - haven't heard that it impacts emissions but it should have a positive impact, as car should be running and firing smoother.
Different front and rear plugs don't matter. Rear are often different as they're rarely changed.

Seems like there's a couple of people with emissions problems at present - the above are the only things I have seen to address.

Anyone else any other ideas ?

by **karlf** » Tue Jul 07, 2009 11:58 pm

I think I'll just put it through as is and hope changing plugs, cleaning filters, using diptain (unsure of spelling) and driving the stones out of it (I'll be coming from edenderry to fonthill to do the test and go flat out the whole way up :lol:

) does the trick. If it fails after that then I'll look at changing Lamda sensor and the cat. I'd get the Lamda sensor off ebay now if I thought I'd get it before monday.

Kace wrote:Replace Cat, you say it's new - are you sure.

Not 100% on that as the previous owner was unsure. But I got under the car and had a look and it looks new, not that that confirms it. I had the invoice number and tried to find out if the CAT came with the stainless exhaust but never heard back from the supplier. As its 18 months since the exhaust was done maybe they have no record of it. I also had the part number and looked it up and the picture showed the CAT was included, similar exhausts that were pictured were shown with no CAT and were a good bit cheaper.
Hopefully the diptain will do the job, my bro-in-law got his de-cated galanza through at second time of asking by using this. It will cost me €28 to find out but I'd rather that than fork out a couple of hundred on a new CAT and Lamda sensor if it could all be sorted with a €10 bottle of emission reducer.

by **karlf** » Wed Jul 08, 2009 12:18 am

Did a bit of searching the web to see if I could find anything to help me understand the process that affects emissions and found these:
http://auto.howstuffworks.com/catalytic-converter1.htm
http://auto.howstuffworks.com/question482.htm
I still dont fully understand it but it did help. It also kinda confirmed some of those suggestions I was asking about:

how it works wrote:Fouled plugs causing unburned fuel to overheat the converter

It also says tat it can take some Cat converters time to heat up to the perfect running temperature and that can affect the efficency of the cat.
Also found this on Lamda Sensors:
http://www.picoauto.com/applications/lambda-sensor.html
It gives a guide on how they work,how to check them. It gives values for voltages across the sensor and what each one means, ie a rich or lean fuel mixture. All I need is an oscilloscope.

by **karlf** » Mon Jul 13, 2009 7:13 pm

I passed the NCT today having the steering rack boot replaced and using celluelous thinners (as recommended by my cousin, {a mechanic} never heard of it before that, could not find diptain). I had also cleaned my air filters and changed spark plugs since the first test. My figures weren't that bad to begin with(see above) but a combination of doing all this got me through. I'm chuffed as I was half expecting to fail again as I had my doubts these would work.
My figures this time were as follows:
Low Idle:
CO_____0.09%
High Idle:
Lamda:0.998
CO_____0.24%
CH_____60ppm