1998 Vauxhall Vectra

Engine Performance problem
1998 Vauxhall Vectra 6 cyl Manual

hi I took my vectra sri for a mot the other day and it failed on emissions I replaced the cat as the mechanic done a test on it and said there wasnt one there.
i also replaced the lambda sensor.
i had another mechanic with a diagnostic who ran a test and said all the sensors were fine and running as they should.
i went back to the garage again and got a reading printed off and they are as follows
co 0.72
COcorr 0.76
co2 13.50
hc 113
02 0.81
^ 1.013
Toil 15
rpm 0
any ideas what it could be I am completly stuck now
May 10, 2010.

Did the car refailt after cat and lambda replacement?. Also there are 2 02/lambda sensors. Was the correct one replaced?

Dave H
May 11, 2010.
Hi yes the car failed after replaceing the lambda and cat I got told the sensors were fine by the diagnostic guy although it keeps failing the emission test at the minute apparently its letting too much fuel through

May 11, 2010.
Is the cars MIL/CEL (check engine light) on? Are there any fault codes stored on cars computer? Repalce the air filter and clean/replace the MAF (mass airflow) sensor. Also add a good fuel system to fuel tank to clean out the injectors etc.

Dave H
May 12, 2010.
Took the car for another emissions test after putting a new lambda, maf sensor and replacing the cat its still saying that its too rich on the petrol ive had 2 guys with a diagnostic machine out to read it and they both say there isnt any faults coming up on the computer.
Is there a way to slow down how much petrol is being let throug so its not burning to much fuel

May 21, 2010.
Fuel delivery is computer controlled. Computer uses readings from MAF/MAP and ECT sensors to determine amount of fuel delivered to injectors. Could be a bad injector or faulty fuel pressure regulator?

Dave H
May 22, 2010.