Failed Mot Exhaust Emission. Can anyone exlplain the following result please.

I have a Toyota Carina E (petrol, 1995). It failed the MOT's emission
test.
The results are listed below and would like your expert opinion as to
what
do you think is wrong.

200k Miles on the clock, runs perfectly well. Good mpg. The expensive
lambda sensor is 3 yrs old. Engine type 4A-FE. The cat was hot when
tested. No engine check light flashing on the dashboard. Slight
vibration on the wheel at 70 MPH.

What if i just take the air filter element out for the emission test?
It worked for my D reg Micra EVERY time. Anyony tried it with these
morden ECU cars ?

Thank you in advance.


Oil temp >= 60 C cooling fan cut in

Fast idle Test: FAIL

Engine Speed 2350-2650 Rpm 2400 Rpm Pass
CO: <= 0.30 % vol 0.97 % vol Fail
HC: <= 200 ppm vol 160 ppm vol Pass
Lambda 0.970-1.030 0.983 Pass

Second Fast Idle Test: FAIL

Engine speed 2350-2650 Rpm 2470 Pass
CO: <= 0.30 % vol 0.74 % vol Fail
HC: <= 200 ppm vol 125 ppm vol Pass
Lambda 0.970-1.030 0.995 Pass

Natural Idle Test: PASS

Engine Speed 650-850 Rpm 770 Rpm Pass
CO: <= 0.50 % vol 0.48 % vol Pass

Overal Result: FAILED

<johnsmile123@hotmail.com> wrote in message
news:1162074456.302162.84390@h48g2000cwc.googlegroups.com...[color=blue]
>I have a Toyota Carina E (petrol, 1995). It failed the MOT's emission
> test.
> The results are listed below and would like your expert opinion as to
> what
> do you think is wrong.
>
> 200k Miles on the clock, runs perfectly well. Good mpg. The expensive
> lambda sensor is 3 yrs old. Engine type 4A-FE. The cat was hot when
> tested. No engine check light flashing on the dashboard. Slight
> vibration on the wheel at 70 MPH.
>
> What if i just take the air filter element out for the emission test?
> It worked for my D reg Micra EVERY time. Anyony tried it with these
> morden ECU cars ?
>
> Thank you in advance.
>
>
> Oil temp >= 60 C cooling fan cut in
>
> Fast idle Test: FAIL
>
> Engine Speed 2350-2650 Rpm 2400 Rpm Pass
> CO: <= 0.30 % vol 0.97 % vol Fail
> HC: <= 200 ppm vol 160 ppm vol Pass
> Lambda 0.970-1.030 0.983 Pass
>
> Second Fast Idle Test: FAIL
>
> Engine speed 2350-2650 Rpm 2470 Pass
> CO: <= 0.30 % vol 0.74 % vol Fail
> HC: <= 200 ppm vol 125 ppm vol Pass
> Lambda 0.970-1.030 0.995 Pass
>
> Natural Idle Test: PASS
>
> Engine Speed 650-850 Rpm 770 Rpm Pass
> CO: <= 0.50 % vol 0.48 % vol Pass
>
> Overal Result: FAILED[/color]

High carbon monoxide (CO) comes from an incorrect air/fuel mixture.
Removing the air filter should not affect the result in a modern fuel
injected engine because the air flow sensor is after the air filter element.

High CO can come from over-advanced ignition timing, leaking fuel injectors,
a bad MAF sensor, PCV, evaporative emissions system problem, or bad oxygen
(lambda) sensor.

Since the car seems to be running well, I would start by checking lambda
sensor voltage and MAF voltage and compare with factory spec.
--

Ray O
(correct punctuation to reply)