Hello,
I took my Saxo 1.4 VSX (1997) in for an MOT and it failed on emissions both
times. The first MOT passed the CO test at natural idle but failed the fast
idle tests. The second time I put some redex in a full tank and drove about
200 miles ragging it quite a bit (this got the tank down to about halfway)
Before I took it in I then filled it right up again, so still some redex in the
system. I drove it hard for several miles right before the test as I did before
also and also took the air filter out. Unfortunately it failed again only worse
this time.
Below are the results of both MOT tests
==============================================
FIRST MOT TEST
Fast idle Test
CO = 0.61% (Limit 0.3) FAIL
HC = 25 ppm (limit 200) PASS
Lambda = 1.002 Limit (1.03) PASS
2nd Fast Idle
CO = 0.56% (Limit 0.3) FAIL
HC = 18 ppm (limit 200) PASS
Lambda = 0.997 Limit (1.03) minimum limit is 0.97 PASS
Natural Idle Test
CO = 0.47 (limit 0.5%) PASS
======================================
=======================================
2nd MOT results
Fast idle Test
CO = 0.68% (Limit 0.3) FAIL
HC = 39 ppm (limit 200) PASS
Lambda = 1.002 Limit (1.03) PASS
2nd Fast Idle
CO = 0.45% (Limit 0.3) FAIL
HC = 71 ppm (limit 200) PASS
Lambda = 1.011 Limit (1.03) minimum limit is 0.97 PASS
Natural Idle Test
CO = 0.68 (limit 0.5%) FAIL
===========================================
Now can anyone tell me what the likely cause of the failure is?
Did the redex do it in? did not having an air filter actually make it worse?
did ragging the car at high revs do it in?
Before the first test I changed my lambda sensor for a new bosch one.
The old one had silicon on it back from the dodgy tesco fuel (in 2007).
Also I had a new (although cheap) catalytic converter fitted about 8
months ago. Could the lambda sensor being crap have damaged the CAT?
I changed the spark plugs around the same time too.
The fuel efficiency is good at about 45 MPG. Its done about 75k
Other problems with the car,
I feel that it lacks power compared to what I expected, it feels like it has
less power than my old 1.2 clio.
When pulling away and accelerating in first and second it sometimes
doesnt go and pauses a bit a few times. The revs dont jump up so
I dont think its the clutch slipping... Also very rarely the rev counter
isnt very smooth when letting off the power and jumps down say to 2500
to 1500 then to 1000.
If anyone can give me some idea of whats wrong I would appreciate it
as I am not sure what to do about it.
Cheers