Hi everyone, could you please help me:

my 94 wrx has failed its mot on emissions. results below.
its failed on the c0.

could it be
- bad lamda?
- bad cat?
- exhaust leak?
- cat not hot enough? (every garage I ask to test at 3.5% says they have to use .3% as has this one - they would not even take it out for a longer run to get the cat super hot!

im going to take it else where but could do with some advise on the readings please.


fast idle test

co 0.95% fail
hc 66ppm pass
lambda 0.99 pass

second fast idle test

co 1.08% fail
hc 55ppm pass
lambda 0.97 pass

natural idle
co 2.33 fail

 

CO is more than likely a cat issue. Was the cat hot when the car was tested?

 

hi, the car has been stood for 18 months, I drove it across town as hard as I could to get some heat into it. it was then left for 25 mins before they tested it. I had to leave it with them so I have no idea if they gave it a run first but when questioned they said the car was up to temperature as per any other car they test.

 

suspect I may have to book another test a bit further away from home maybe? its difficult cos its not taxed or mot at the mo which makes getting it warm before a test difficult.

 

Find a decent tester and tell him what's up.

 

bit of an update:
I tested the output voltage of the lambda sensor with the engine warm and idling and it was stuck at around 0.4 volts. so ive fitted a new lambda but its the same. it will flick up and down between 0.1 and 0.9volts if I rev the engine but it wont cycle at idle.
I suspect the car is not dropping into closed loop? why would this be? coolant sensor maybe?

 

you just need a "friendly" M.O.T tester ...that all

 

Hi,
I had the same problem at my mot for a 95 WRX RA. I found this pic on a similar post, printed it out and took it back. They passed it straight away. Depending on the year of manufacture the import won't need a cat test if they can't find the exact model on the database. Might help you a little.

 

the universal lambda for £17 and some drop links for £13 off ebay have done the trick - shes passed! also took that BET info down too and they were alright with it.

 

Well done, you can relax for 11.5 months now!