MOT Fail - erratic lambda readings
#1
MOT Fail - erratic lambda readings
Hi Guys - I hope you can help.
My 2000MY Impreza Turbo Classic with 110K miles has just failed its MOT on emissions. Could anyone please suggest why the lambda readings should be so far adrift from each other on the fast idle test, and what the cure might be?
The MOT Centre suggested faulty MAF but the car is running sweet as a nut, with normal mpg.
Many thanks
Pete
PS sorry about the formatting - the first figure on each line is the required limit - the second figure is the test result
Here are the readings:
DESCRIPTION Limits Actual Value
Engine Oil Temperature Min 80 Deg C 95 Deg C OK
Fast Idle Test: FAILED
Engine Speed: 2450-3050 rpm MANUAL CHECK Pass
CO: <= 0.300% -0.004% Pass
HC: <= 200 ppm 2 ppm Pass
lambda: 0.970-1.030 2.741 Fail
Second Fast Idle Test: FAILED
Engine Speed: 2450-3050 rpm MANUAL CHECK Pass
CO: <= 0.300% -0.006% Pass
HC: <= 200 ppm 1 ppm Pass
lambda : 0.970-1.030 1.083 Fail
Natural Idle Test: PASSED
Engine Speed: 750-1050 rpm MANUAL CHECK Pass
CO: <= 0.500% 0.371% Pass
Overall Result: Exhaust Emissions Test FAILED
My 2000MY Impreza Turbo Classic with 110K miles has just failed its MOT on emissions. Could anyone please suggest why the lambda readings should be so far adrift from each other on the fast idle test, and what the cure might be?
The MOT Centre suggested faulty MAF but the car is running sweet as a nut, with normal mpg.
Many thanks
Pete
PS sorry about the formatting - the first figure on each line is the required limit - the second figure is the test result
Here are the readings:
DESCRIPTION Limits Actual Value
Engine Oil Temperature Min 80 Deg C 95 Deg C OK
Fast Idle Test: FAILED
Engine Speed: 2450-3050 rpm MANUAL CHECK Pass
CO: <= 0.300% -0.004% Pass
HC: <= 200 ppm 2 ppm Pass
lambda: 0.970-1.030 2.741 Fail
Second Fast Idle Test: FAILED
Engine Speed: 2450-3050 rpm MANUAL CHECK Pass
CO: <= 0.300% -0.006% Pass
HC: <= 200 ppm 1 ppm Pass
lambda : 0.970-1.030 1.083 Fail
Natural Idle Test: PASSED
Engine Speed: 750-1050 rpm MANUAL CHECK Pass
CO: <= 0.500% 0.371% Pass
Overall Result: Exhaust Emissions Test FAILED
Last edited by Pete The Biker; 09 October 2010 at 02:54 PM. Reason: Battling with formatting!
#3
The car is bog standard, with no additives in the fuel.
I did 100 miles on Thursday on country A roads and motorway. Today (Saturday) I drove 5 miles to the MOT test centre and they did the MOT within the next 45 minutes.
Pete
I did 100 miles on Thursday on country A roads and motorway. Today (Saturday) I drove 5 miles to the MOT test centre and they did the MOT within the next 45 minutes.
Pete
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Full Cars Breaking For Spares
28
28 December 2015 11:07 PM
Mattybr5@MB Developments
Full Cars Breaking For Spares
12
18 November 2015 07:03 AM
Sam Witwicky
Engine Management and ECU Remapping
17
13 November 2015 10:49 AM