High Lambda reading!

[Deany]

eyup me again.

Had cup in for test today, failed on brakes (need bleeding) and high lambda reading after 2nd fast idle test.

Now the CO 90%) and HC (5ppm) levels are fine so the cat is ok.

Lambda reading was 1.10 first fast idle and 1.07 second fast idle. pass rate is between 0.97 and 1.03. Surprised me as it was bang on 1.03 last time it went in a month ago.

I do have a twin tailpipe exhaust could this have an effect on it? Dont think there are any blows in the system


What do I need to change? Pre cat lambda? Post cat? Swap them over?

 

[harmo]

Really sounds more like a lambda sensor to be honest! I had the car in for NCT (irish MOT) and failed on similar emissions. Changed the lambdas and sorted. Did you decat the car recently?

 

[Dan519]

do you have an exhaust with a big tailpipe?

 

[Deany]

car never been dacatted.

danny its got 2.5" twin tailpipes. was thinking about blocking one up

 

[Dan519]

yeah that'll be the cause of it. probe will need to go further in and block one pipe off with a wet cloth while the test is done.

The readings you have show it being lean, so air is being sucked in

 

[Deany]

cool. ill get it back in next week and do that then, failing that itll be the week after when i put the yozza on