Emissions Fail again :(
 

Hi all, I know there's been a lot of posts about emissions, so sorry for the repeat.

I had my WRX MOTed and it failed on emissions:

Fast Idle Test
CO- 1.02% vol (fail)
HC- 51ppm (pass)
Lambda- 0.988 (pass)

2nd Fast Idle Test
CO- 0.60% vol (fail)
HC- 523ppm (fail)
Lambda- 1.365 (fail)

Before this test, I had an error code- P1312 bank 1. After the test, I replaced the lambda sensor (but it was from eBay for £50 and I had to cut the wires to fit it). I also had the engine Terracleaned. I just had it re-tested and it failed again, with the same-ish results!!

The car has been modified- it has an adjustable actuator, a Cosworth panel filter, has been retuned to 270bhp, a 3" Cobra 200 cell sports cat, a 3" mid section and a Nur spec back box.

Any advice to get me through the MOT would be great, please. Thank you very much.

What year is it ?

A sports cat unless uber uber hot is never going to achieve the results required of a normal cat if your tester is putting it through as a catted car .

Your lambda results in the 2nd fast idle are not good which to me says lambda fault still .

If your car has you've put through as s catted car replace sports cat with normal cat .

Buy proper sensor and get cat hot before test.

http://www.lambdasensor.co.uk
proper denso ones