Cat damage with leaded petrol

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Thu 11 Aug 2005 16:51
Cat damage with leaded petrol - Harmattan
With reference to a Q & A in last week's HJ Telegraph column from someone planning to drive to North Africa, what would be the physical effect of using leaded petrol in a catalysed vehicle? At some point the active material in the cat is presumably neutralised or destroyed and it has to be replaced to meet the MoT test, but are there any side effects such as bad running or confusion for the ECU once the damage is done? Might it not also be cheaper if possible to remove the cat before travelling (replace it on return) or does that give the ECU brain damage?
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Thu 11 Aug 2005 16:56
Cat damage with leaded petrol - Adam {P}
I remember during the petrol strikes having to put leaded in an unleaded car.

The mechanic said he was amazed it even ran.
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Adam
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Thu 11 Aug 2005 17:04
Cat damage with leaded petrol - Colonel Panic
The small amounts of lead in the later leaded petrol wouldn't have caused problems if used occasionally (I was told by a researcher at an Abingdon fuel company lab) I too used a fair bit during the fuel protests and subsequent MOT emmissions were fine.
Best thing to do if find out the amount of lead they have, and compare it to the last 4* you could get here.
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Thu 11 Aug 2005 17:06
Cat damage with leaded petrol - Adam {P}
Re-reading my post gives the impression that there was some damage as a result of using leaded (hence the mechanic!).

That wasn't the case - the car was in for something else.

For general interest, it was a 1996 VW Polo 1.0.
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Adam
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Thu 11 Aug 2005 17:28
Cat damage with leaded petrol - pettaw
AFAIK proper 4star hasn't been available here for a few years. All the so-called 4star isn't leaded petrol but LRP which contains an additive to protect valve seats but I think this also isn't great for cats.
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Thu 11 Aug 2005 18:05
Cat damage with leaded petrol - Victorbox
"proper 4star hasn't been available here for a few years"

If you are in the UK then real 4-star petrol is still available all over the UK from Bayford. Go to www.leadedpetrol.co.uk/ to find the nearest petrol station selling it.
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Thu 11 Aug 2005 20:07
Cat damage with leaded petrol - jc
Leaded petrol will not physically damage a cat.,just chemically-however over a long period on the correct fuel it will recover some of the reactions.
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Thu 11 Aug 2005 20:44
Cat damage with leaded petrol - Aprilia
The lead coats the cat's reactive surface and reduces its efficiency. It also tends to leave deposits which bung-up the EGR valve - so can give other running problems.
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Fri 12 Aug 2005 14:39
Cat damage with leaded petrol - Harmattan
Thanks, Aprilia. I was wondering about the secondary effects. Would the use of some form of agent, say those sold for cleaning injectors, have any impact on removing deposits from the EGR valve?
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Fri 12 Aug 2005 15:42
Cat damage with leaded petrol - GolfR_Caravelle_S-Max
I'd like to ask anyone tecchie enough what the burnt (and unburnt) residues of 5-10% xylene in my petrol tank might do to a catalytic converter.
Also, with approx 75ml Acetone per 50 litres 97/98/99 Ron fuel AS WELL as the Xylene?

Thanks
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Fri 12 Aug 2005 23:28
Cat damage with leaded petrol - Colonel Panic
No deposits, both burn and or evapourate very readily and cleanly.
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Sat 13 Aug 2005 09:04
Cat damage with leaded petrol - jc
A blocked EGR valve should not cause any running problems-it will increase emissions(NOX)slightly and actually improve part-throttle performance(it does not operate at at wide-open throttle.
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