Help needed with Lamda readings.
 

Hi all just purchased my first Subaru it’s a 2006 WRX running approx 340 BHP.

I purchased it a few days ago knowing it failed it’s MOT back in November and apparently it’s not moved much since, just a quick blast around the block to keep things ticking over by the previous owner.

It failed on

Exhaust Lamda reading after 2nd fast idle outside specified limits.

Exhaust Carbon monoxide content idle exceeds default limits.

Exhaust Carbon monoxide content after 2nd fast idle exceeds manufacturers limit.

CO level was 1.01% the limit was 0.50%

Lambda was 0.937 which was under specified limits.

So it failed on CO levels ana Lambda readings but passed on the HC levels.

My predicament is this it currently has an M2 Motorsport sports CAT on the downpipe with a decat 2.5” all the way through to an Afterburner Exhaust Exit.

My plan was to do things gradually over the Summer months to get it on the road as in buying standard exhaust with CATs but after looking into it even buying second hand that is going to cost approx a grand with fitting which is a waste of money because I will just put the exhaust back on that it currently on there anyway.

Is the Sports CAT a cheap one, would purchasing a better quality one make any difference?

I know warming up the CAT is essential prior to MOT but is there anything I can do as a quick fix that isn’t going to cost the earth because now I’ve bought it I just want to drive it.

Ah the good ol sports cat, they need an italian tune up before the MOT. Basically get them red hot and send in for the emissions part of the test.

Thanks for replying so hopefully it’s a simple fix to get it through the MOT then just make sure it’s boiling hot. Appreciate it.