mot today

at idle it's reading 2.5%

at 2500 rpm it's reading 6%

the tester has informed me it ought to be at 0.2% and he can't let it sneak through with 30 times the allowed number.

The car is a 95 sti ra with power FC, breathing mods and bigger injectors.
it has a sports cat in the centre section and was mapped fairly recently by JGM to a little over 300/300

The current theory is that something is broken - any suggestions?

 

What are the readings exactly?

Lambda specifically which effected by fueling. If thats correct its down to the cat to sort the others.

I presume lambda sensor is faulty

 

Thanks for looking in Simon


I think it was CO - I can get the exact details later today.

I imagine something that obviously wrong would have been picked up when you mapped it last summer so presumably it's busted since then.

edit: CO was high, lamba was low.

 

What was lambda exactly?
Lower number is richer so could well be a faulty lambda so ecu is seeing low voltage and thinks it is lean and chucks fuel in.

Can check it

 

I'll see what information I can get when I see him and will drop you a mail.

thanks

 

lambda was at 0.8

 

Massively rich then.

Would suspect lambda sensor or a pipe leak or some kind.

 

got a new sensor on order and i guess ill be hunting leaks this weekend then...

ta

 

If its still miles out let me know and I will come and take a look

 

sensor on (why did they put it there?)

do i need to reset ecu or anything?

if so do i just unplug the battery overnight or do i need to do anything clever with the fc commander thing?

ta

 

If its still in headers I would recommend moving to the downpipe.

No the only reset on the pfc erases the map.

Is car on it etc?

 

If its still in headers I would recommend moving to the downpipe.

No the only reset on the pfc erases the map.

Is car on it etc?

 

the sensor is in the headers - not sure whether there's a hole in the downpipe for one or not as I believe that's a decat (cat is in the centre section)

the map is still there

its gonna get a probe stuck up it again monday with any luck so i can see whether its made any difference or not.

it still smells pretty petrolly out the back and makes some fairly thick smoke (not a funny colour or anything, just lots of it) when running so im guessing it's not solved the problem entirely.

would the powerFC immediately adapt to a properly functioning sensor then ?

 

Yes it would.

Intercooler leak?