Are they testing emissions correctly if it's running on LPG ??? 

Unless they have a "switchable" tester, or a tester calibrated for LPG (they then have to do a calculation to get the "right" value) they should not be doing the emissions test.

http://www.motuk.co.uk/manual_730.htm

para 7

Marks DTM Calib wrote on 01. Feb 2011 at 21:22:


Whats one of them then ....   


Maxscan GS500 here ...  should still read, hopefully, the relevant bits ..  but it's no where near as "all singing" as an opcom ..

Had Keith around today and slapped the reader on ... results are :

Fault codes - engine not running

P0650 - MIL light inop !!!! and confirmed it don't work ..

and a load of transmision faults

P0706
P1740
P1781
P1870
P1890

Started engine and rechecked ....  additional fault

P0141 - O2 sensor heater .... I wonder if that is the cause of the emissions problem ??

Now this is his 2.2 running on petrol not LPG at idle..  Live data, I couldn't find a "block learn" so this is what I got ...

FUELSYS1 - CL
FUELSYS2 - N/A
LOADPCT% - 17.6
ETC C - 70
SHRTFT1% - -0.8
LONGFT1% - 11.7
RPM - 772
VSS 0
IAT - 22
MAF - 2.89
TP % - 2.7
02B1S1 - 0.135 - 0.74
SHRTFTB1S1 - -2.3 - +1.6
O2B1S1 - 0.425

Engine off, Cleared all faults, rechecked .. just the P0650 as expected.

Restart engine and check again

P0650
P0141 - O2 sensor heater

I'll let him take you through the rest of the fails .. but nothing a front suspension rebuild won't cure ... 

HTH the diagnosis by those who understand these things ... 


If it needs more we'll arrange for it to be redone .. but live data on the GS500 is limited to what I've put up ..

A Thought  ... perhaps we should have checked it running on LPG as well ..

Thanks for the help Nigel.

Another question for the guys out there - The MOT station quoted for replacing 2 lambda sensors but i'm only aware of one on the exhaust after the cat. Is there another? By the way they wanted £400 for the pair fitted!!

I just checked the post cat sensor and I can't get 12V on any of the wires so wonder if the voltage isn't getting through to the heater. i'm assuming it is a high resistance wire with 12V applied to create heat?
There are 4 wires Black, Grey and 2 white.

Kevin - The car was up to temperature.
I don't have a lot of faith in the original test station so will try somehwere else to check the emissions. Any recommendations in Swindon anyone.

I've had a look at the track rod ends and they are shot - lots of side to side rocking. Is it worth just changing the ends or the whole assembly?

The wishbones seem ok and only one side has any top to bottom rocking but I think that may be wheel bearing.

pigtown wrote on 07. Feb 2011 at 13:13:


Yes, it will be the 2 white wires. They are controlled by the ECU, though, so it's possible it has closed-loop heating of the sensor. It may not apply 12v to these wires permanently. It certainly won't apply anything until the engine's running.

The best bet is to measure the resistance between the two white wires into the sensor with as multimeter on ohms in case the heater is open circuit. 

Quote:


No. This sensor is only used to check that the cat is working. The front (pre-cat) sensor is used for mixture control. The post-cat sensor has no effect on the emissions or engine running. Hence my thoughts that the main problem is elsewhere.

Kevin

pigtown wrote on 07. Feb 2011 at 19:16:


I don't know for sure for the 2.2 sensors but typically would expect to see 10-15 ohms. 5.5M is an open circuit for all practical purposes so that explains the trouble code (but not the emissions problem, I'd say ).

As for the pre-cat sensor it'll be right up on the downpipe or even the exhaust manifold. Probably still best accessed from the underside though.

Kevin

pigtown wrote on 09. Feb 2011 at 20:07:


OK. If that doesn't cure it try swapping the new sensor with the pre-cat sensor so the new one is pre-cat and the old one post-cat.

Kevin