Emmision Failure

[Guest EmissionsAreKillingMe]

Hi there, this is my first post. I have an ongoing emission problem. Started 2 years ago whenthe cat and lambda sensor were replaced to sort it out. Then for last years MOT it failed again so went to ford main dealer hoping for some expertise! To cut a long story short, they couldnt get it to pass until they took it out for a magical 10 minute drive and then it passed with flying colours??? this despite me driving it for half an hour before so that they could put it straight on test when I got there!

Anyway that brings us to the present, at which point I found this site. Having read the many posts of similar problems, it seemed to me like the majority of garages just seem to work on a process of elimination, of which I too am capable. So as the lambda sensor seems to be the most common fault, and I didn't know if it was a genuine ford part, I decided to replace it, feeling confident I took it for emmission test, and you guessed it, it failed! Next on my list was the Auxiliary Air Pump, which upon removal and strip down, was found to contain a pile of rust where a motor once was. So I now thought I had hit the jackpot, until I phond the ford garage and was quoted

[Topbloke]

do you have a print out of the emmisions and what were they

[Guest EmissionsAreKillingMe]

Hi, test results were

 

fast idle co=2.87 hc=174 lambda=0.92

2nd fast idle co=3.01 hc=175 lambda=0.91

idle co=3.19

 

so hc passed but everything else fails! Help

[Guest EmissionsAreKillingMe]

Hello again, just spent the afternoon under the bonnet. Blanked off auxilliary air pipe. Tested inlet air temp sensor - working ok. Decided to test engine coolant temperature sensor, removed thermostat housing to get to it and found thermostat to be not sitting correctly. Tested thermostat in kettle and it only opened as water started to boil. Replaced thermostat, refitted and measure voltage from temp sensor which seems fine. Also my front heater has now started working again after about 16 months.

Could this thermostat be the cause of all my emmision problems???

[Guest EmissionsAreKillingMe]

ps, when i first started it after new thermostat, it put out loads of white smoke which it doesnt normally. After taking it for a thrash it cleared and is fine now. Maybe this was the control system re-adjusting?

Will take for emmision test on monday

[Masked Marauder]

If the engine was not getting up to running temperature then the engine would be running a higher air/fuel ratio which could have been the cause of your problems.