Yet another NCT Emissions Fail

[sidewaysreilly]

So she passed.......but, emissions were almost too low! Lambda 1.02 (lean) and CO 0.04!

What did I find? Well the Manifold gasket had failed between it and the Head (this will lead to dilution of the air causing the ECU to dump in more fuel) causing the rich Lambda reading 0.96. I got a genuine Mazda metal gasket. Dont skimp on this if you are going Turbo.

I knew the Cat was dodgy last year so I cut it out and welded in a Mk1 JDM one. Same length approx. but bigger cross section.

Why so bloody lean tho. Im running a wideband and the Ling ECU is set to the recommended defaults for this. Master fuel perhaps ???

So she is ok for another year but it needs as bigger exhaust so a 2.5" is on the cards.

[Steve]

do you have a knock sensor? Worth getting one if you suspect you are running lean.
How are your idle settings?

[sidewaysreilly]

Yeah its running with a knock sensor Steve. Its just lean under vacuum at high idle. Might just up the settings for the wideband. Its at 22 (recommended) so I might up it to 24.