boon Posted September 8, 2011 Share Posted September 8, 2011 thanx up front,just got d2 4.0L v8 with multi point injection system back from MOT failed on emmisions,lamda sensors reading to high getting various advice on what to do,Has anyone had this problem?and a possible solution that will definatly work.cheers guys. Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted September 11, 2011 Share Posted September 11, 2011 There are several things to do. Obvious one is check or swap the lambdas, i fitted fuel part ones for about £80 and when I unwrapped them they were NTK parts anyway (That's NGK's trade brand). You can dissable the lamdas and go closed loop, it ignores the lamdas and runs from the Mass Air Flow meter instead. Change the oil, I'm not kidding. A mate of mine did his and checked the oil filler with the MOT test probe before and after, as well as the tailpipe. You get oil in the cylinders and exhaust gas in the crankcase. Check and clean all the breather filters. You can adjust the MAF, but as above with Lambdas it's set up to £ignore" the MAF once it's running. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 11, 2011 Share Posted September 11, 2011 Multipoint = on LPG? In which case it should be subject to a non-cat test, and as such it should run from lambda signal there should be no problem getting a pass... Has it been tried on petrol? Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 11, 2011 Share Posted September 11, 2011 If all the other readings are good except for a high Lambda reading,chances are its just a leaking exhaust system.Can you please post the Co and Hc readings too. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 12, 2011 Share Posted September 12, 2011 I'm slightly confused by RRB's post - never heard of EMS ignoring the MAF "once running", surely it's one of the major inputs to the system I'm with AllyV8 on this one. Quote Link to comment Share on other sites More sharing options...
boon Posted September 12, 2011 Author Share Posted September 12, 2011 If all the other readings are good except for a high Lambda reading,chances are its just a leaking exhaust system.Can you please post the Co and Hc readings too. will do but bare with me i will have to revisit as the print out is not very clear,no ink in his printer. Quote Link to comment Share on other sites More sharing options...
boon Posted September 12, 2011 Author Share Posted September 12, 2011 Multipoint = on LPG? In which case it should be subject to a non-cat test, and as such it should run from lambda signal there should be no problem getting a pass... Has it been tried on petrol? the tester said he was not allowed to do the test on lpg although its been done for the last 3 years i have had the car, and your right no problems.i will be asking questions thankyou. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 13, 2011 Share Posted September 13, 2011 the tester said he was not allowed to do the test on lpg although its been done for the last 3 years i have had the car Hmm, he is mistaken, if you present the car running on LPG, he has to test it that way. If you present it running on petrol he has to test it that way. Ask some questions, if he argue the toss, ask to speak to his Authorised Examiner, if no joy talk to VOSA. Quote Link to comment Share on other sites More sharing options...
sussex-landy Posted November 4, 2011 Share Posted November 4, 2011 I have just had the same issue on my Range Rover 4.0 2001 which I find curious as there is no leaks i can see in the exhaust and you would hear it blowing. My printout shows the following. CO - 0.00 % vol HC - 1 ppm Lambda - 1.151 fail min 0.950 max 1.090 Seems strange as everything else is perfect to a point I would question his machine as I cant believe I get a 0.00% CO on both fast idles. Garage said put some redex in a blast it up the motorway which I am going to do on Sunday on a 400mile round trip. Also going to clean the air filters and tighten exhasut manifold and anything I can see related to air ot exhaust gases. What I dont understand is how a leak makes the lambda worse and if its an exhaust surely it blows. When my S3 had a leaking exhaust you could hear it popping. Thanks Robert Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 7, 2011 Share Posted November 7, 2011 As the pressure pulse goes past the leak the low-pressure wave that follows it will suck in air, which contains more oxygen than exhaust gas, which leads to a rich reading on the lambda sensors (they measure exhaust gas oxygen). Doesn't take much of a leak and you may not hear it. Quote Link to comment Share on other sites More sharing options...
sussex-landy Posted November 7, 2011 Share Posted November 7, 2011 So are you saying there could be an issues with the exhaust before the lambda sensors which looks like it would be closer to the manifold I think. This wouldnt make a blow noise or let some gas out which would be visible. Thanks Robert Quote Link to comment Share on other sites More sharing options...
peterdon Posted November 7, 2011 Share Posted November 7, 2011 the tester said he was not allowed to do the test on lpg . As above, absolute rubbish, it must be tested on the fuel it is presented with. Quote Link to comment Share on other sites More sharing options...
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