Cat Converter Problems

[simonbartlett]

Hi I would like some advice, I have a RX300 year 2000 which is converted to Lpg. The car has been converted for about 25k with no problem exept we keep getting fault code P 0420, we had the cat changed by lexus dealer which stopped the problem for about 12k but it has returned.

The question is does lpg destroy cats and can we fit an o2 sensor simulator to fool the car into thinking that the cat is ok. The car has just passed the mot at lexus today so i guess the cat isnt to bad but the lights on dash are annoying. Thanks for any help

[SJT]

Simonbartlett

I also run my RX on lpg. I can't answer your question but I will be very interested to see any replies.

I love my lpg so I hope nothing too frightening comes out of this!

Steve...

[leedsunited]

Who did your conversions, i am struggling to find anybody interested in doing it on the RX

[SJT]

I used www.lloydash.co.uk and cannot fault them.

Steve...

[simonbartlett]

HI I used a company in bournemouth they made a good job on two cars for me and I am very please with the car on lpg. Can you let me know if you have got flashlube on yours because i was told that it wasn't required, Also how many miles have you done on lpg?

[SJT]

Flashlube is fitted to some cars by my installer but they simply refused to fit it to mine. I have done approx 20k on lpg now and at 38p its saving me a fortune. No problems to report to date.

Steve....

[simonbartlett]

Do you know why they refused to fit flashlube

[SJT]

Do you know why they refused to fit flashlube

I'll ask them next time I call in for specific reasons. When originally installed they just said that it was not necessary.

Steve

[cnrke1]

I'm contemplating converting my RX. What is the flashlube?

Excuse my ignorance.

[simonbartlett]

Flash lube is basically an oil which you put in a bottle under the bonnet and it is fed in with the gas to lube the valves etc, 1 litre lasts about 5k miles I think.

[nohablaespanol]

I drive a '98 HARRIER-RX300 on LPG and cannot fault it. The reason for the flash lube is to lubricate the valve seats/stems as some more advance engine designs do not like being run on LPG and it is reported that the Lexus range is one of these. They can suffer with valve seat regression, which means the valve seats wear out giving reduced performance and other associated engine problems. Another problem with LPG is the different burn characteristics between it and petrol. The LEXUS has a variable valve timing and since LPG burns slower it can leak past the valves at high engine speeds when the valves are being timed open. OK so the flash lube may protect against all these problems and prolong the engine life, but burning oil in an engine will block up the cat and shorten its life. Me, worry, I just drive it :D

[simonbartlett]

How long have you had your harrier on lpg and how many miles have you done?