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[Dr A. 33 1.5IE]

Dear Alfistas,

My Alfa 1.5IE now has 210.000 Kms on the clock its an every day use car. Last week I payed a visit to an exhaust system specialist because I could hear a clanking noise coming from the exhaust piping system especially when off from stationary. The result was that my catalyst has given up its spirit and that the whole ceramic body has detached from the metal casing and that what was producing the clanking noises.

So I replaced my catalyst with a Bosal one.

What I have noticed just before i replaced the original catalyst fuel consumption increased (around 10lit/100kms) from what it used to be (9lit/100Kms). Now in the process of testing the fuel consumption it looks like that so far it is around 8.5lit/100Kms, so thats the good new.

On the other hand the car now produces a heavier exhaust sound and when I try to press it, a bit it seems like that it has a kind of a 'lag' before pulling properly.

So what's the case?

1.Does the car runs a bit better that before with the new catalyst in terms of fuel efficiency (maybe on a leaner mixture)
2. Does the new cat affected the car's 'go' or is it something else.

Thanks in advance!
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1994 Alfa 33 1.5 IE Cat. 220.000Kms and still going strong!!! (Από την Αθήνα και τώρα στην Λευκωσία)

[gritsop]

Hi,

The heavier note on the exhaust is due to the lack of the middle silancier. OEM catalysts feature 3 chambers; front and middle contain the catalyst itself and the 3rd one is the silancier. Aftermarket catalysts do not have a silancier, thats why you can hear a heavier note from the engine.

Have a look also on the force that the exchaust fumes leave the tailpipe. You will see a more intense wave of gases leaving the tailpipe. This is a nice thing to have as the motor breathes easier and becomes more free reving.

What about the Lambda sensor? Is it within specs?

Regards,
_________________
Thanassis Gritsopoulos
1991 Alfa 33 1.4 IE
2001 Alfa 147 1.6 Distinctive

http://www.alfa-restoration.co.uk
Parts Shop: www.alfa-restoration.co.uk/shop

[Dr A. 33 1.5IE]

Hello Gritsop,

No I haven't tested the Lamda sensor. As I said last two weeks or so my Alfa topped at its best a bit over 10L/100Kms whereas I usually had a figure around 9L/100Kms.

By the time the cat was replaced the figures seems to drop to normal again. So I assume that due to the worn catalyst probably the Lamda sensor was running a bit to the rich side of fuel consumption. Now is back to normal I think!

I have read your article @alfarestoration. Yes the car above 2500rpm runw smoother and also at 120Km/h on the highway I used to read 3950rpm. Now for the same 120Km/h I read 3800rpm. Why? Probably as you mentioned is that the car breathes a bit better now.

The difference to what it used to be before is below 2500rpm. The car in medium accelleration it is less kean to go and sometimes I can feel a few staters/cuts as the car gets up to speed. Above the limit of 2500rpm the car simply flies with less effort that before.

So what could it be that makes the car behave a bit funny but not annoyingly enough to call it a problem.

Thanks again...
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1994 Alfa 33 1.5 IE Cat. 220.000Kms and still going strong!!! (Από την Αθήνα και τώρα στην Λευκωσία)

[Admin]

[eagle3]

You may need the injectors cleaning as well. I got mine cleaned and the engine is much smoother at low revs now.

Cost of ultrasound cleaning was just €35 for the four at a local Bosch specialist. I removed them and replaced them myself. I was told the rubber seals were still good and didn't need changing(the car has 90,000km on the clock). Thanks to gritsop for his feature in the restoration section.
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Alfa33 QO 1984
Alfa33 1.3i.e. 1994

[Dr A. 33 1.5IE]

Hi Alfistas,

Actually what is causing the car to statter a bit a low revs is that the car is been driven in stop and go traffic everyday and about 7 miles (11kms) of heavy traffic highway, having no chance to 'breathe' properly and having the sparks cleansed a bit.

After a good thrush though things got better. The car needs the open road from time to time but I haven't got the time for it. Anyway that's life!!!

Regards
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1994 Alfa 33 1.5 IE Cat. 220.000Kms and still going strong!!! (Από την Αθήνα και τώρα στην Λευκωσία)