Make a donation

Author Topic: High Lambda reading on Exhaust gas tester  (Read 2780 times)

Offline omeydz

  • Won't Shut up.
  • *****
  • Thank You
  • -Given: 3
  • -Receive: 50
  • Posts: 914
High Lambda reading on Exhaust gas tester
« on: October 28, 2015, 10:00:20 pm »
Hi.

Had a pre-MOT test and the lambda readout was 1.27 and pass is 1.03.

This is with a thoroughly warm engine and ECU map is stock VW map.

Its a code CAXA 1.4 TSI 122bhp engine.

Any ideas what could have caused this? 

Last year it scraped a pass after 3rd or 4th go on the analyser, again with warm engine and stock map.

Been told by master tech mate it could be the cat, lambda sensor, or leak in the exhaust/intake..

Intake is new and exhaust has been apart recently and sealed up on refit and leak-free so can discount these. No engine management lights. Recently did fuel treatment BG44K few tanks of fuel ago if that makes any difference?

Any help much appreciated
Recently back on the forum! Good to be back
Current Rides
Mazda RX8 231bhp ( very different little rocket lol!)
----
SOLD
2011 Golf MK6 1.4 TFSI R20/GTI Hybrid - DSG converted *world first!*
2007 MK5 Golf 1.4 FSI
2007 Golf MK5 GTI DSG
2008 Audi A5 3.0TDI

Offline pudding

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 2
  • -Receive: 690
  • Posts: 8354
Re: High Lambda reading on Exhaust gas tester
« Reply #1 on: October 29, 2015, 04:12:23 pm »
Was that the CO2 reading at idle?  If so, that's massively high.  Should be well under 1!

Lambda faults would definitely throw up an engine management light.  Has it been fault coded and have you looked at the idle and part throttle long term fuel trim measuring blocks?


2007 ED30 | 2009 TDI 140 | 2016 BMW 330D

Offline Dan_FR

  • Just look at my post count
  • ******
  • Thank You
  • -Given: 132
  • -Receive: 189
  • Posts: 1845
  • wait...what?
    • Email
Re: High Lambda reading on Exhaust gas tester
« Reply #2 on: October 29, 2015, 05:16:28 pm »
1.03 limit is the Lambda/AFR - a pass is 0.97 to 1.03 from memory.

 1.27 is massively lean. Check what the cars lambda sensor is reading as it could be duff.
TFSI... Revo Stage 2+... . WMI.... VCDS HEX + CAN, MPPS, VAG Commander & VAG tacho - South Wales

Offline omeydz

  • Won't Shut up.
  • *****
  • Thank You
  • -Given: 3
  • -Receive: 50
  • Posts: 914
Re: High Lambda reading on Exhaust gas tester
« Reply #3 on: October 29, 2015, 07:28:39 pm »
CO readouts were normal. Its lambda thats too high.

Thanks will check tomorrow!
Recently back on the forum! Good to be back
Current Rides
Mazda RX8 231bhp ( very different little rocket lol!)
----
SOLD
2011 Golf MK6 1.4 TFSI R20/GTI Hybrid - DSG converted *world first!*
2007 MK5 Golf 1.4 FSI
2007 Golf MK5 GTI DSG
2008 Audi A5 3.0TDI