emissions trouble, HELP!!

cogiebear

hey all,

ive recently put my car through the NCT twice, and both times it failed on the emissions! ive brought it to 2 garages, the first garage said he could find nothing wrong with the seals etc, the second garage tested it, cleaned it, flushed it, and made me spend over 100 quid on it! when i put the car through the test the second time, it failed AGAIN! this time the idle emmisions where higher than before.

can anyone tell me what could be wrong with it!?

its only recently been serviced etc so im stumped

thanks
CB

MarkoC

CAT or faulty lambda sensors aro most common problems in these cases.

biko

Please post the numbers from the NCT report.

cogiebear

thanks the no. are as follows:

Low idle: CO 4.59vol%
(680rpm) HC 194ppm

High idle Lambda 1.00
(2,980 rpm) CO 0.42vol%
HC 65 ppm

Engine/oil Temp 88oC


This is the second test which was done today

Hal1

I agree with MarkoC oxygen sensor more likely. Some recommend using diptane to lower emissions and driving for a while to bring everything up to temp and blow out crap from engine.

beam99

o2 sensor or cat most likely, Did the garages not do a emissions test to check it? What did they check? What make of car is it?

cogiebear

yea, they did a check, they put in 2 flushes into it aswell, when i brought it into the garage during the week, the emmision were down to 2.05 vol% but its meant to be at .50vol%.

the car is a 00 old model opel corsa

Tea drinker

are there two o2 sensors on this car? Would he then replace both of them?

shamwari

Tea drinker wrote: »

are there two o2 sensors on this car? Would he then replace both of them?

If the car has two sensors then
Sensor1 controls the fuelling and mixture
Sensor2 just monitors the CAT's performance?

AFAIK thoses Corsa's might only have one.

Has anyone scanned the car for faults and read the live data to see that the sensor is switching properly? Is the engine reaching correct operating temperature (thermostat ok?)

Also what mileage is on that car? And do you have any current or previous running problems with it?

cogiebear

nope nothing like that has been done, the feller in the garage went over it for loose fittings etc and he said it was fine, the second garage said he checked it all and then put in a flush.

when i first got it, a boyracer decided to tamper with it, timing chain was loose, and the sprocket was on backwards, altinator belt was too big an to narrow, airintake was some stupid performance thing.

there's 62k miles on it,

shamwari

I would get the car scanned and the O2 sensor output checked to see what's happening. There could be a fault elsewhere which could be causing the sensor to stay high or low, and screw up the emissions. Changing parts on a hit-and-hope basis is a good way to be spend a lot of money you don't need to

shamwari

cogiebear wrote: »

airintake was some stupid performance thing.

there's 62k miles on it,

Sorry just copped this bit, what exactly was done to the intake? Was the airflow meter messed with in any way?

cogiebear

the airfilter was taken off and some steel performance filter was put onto it, which i took off straight away,

shamwari

Ah, a K&N job by the sounds of it. The airflow meters in those Corsa's gave a heap of problems too, and sometimes they screwed the emissions up no end. Again, I reckon you should have the car checked as I suggested above. There are a number of other things that can gripe up the emissions on those things.

Given that the car was in a boy racers hands, the cat and the O2 sensor will have both led a hard life!