exhaust emissions lamda reading outside limits

belskee · Post by **belskee** » 07 Jan 2015, 15:42

Finally got the beast (late 00 v70 t5 ex plod) in for the mot and failed on the emissions, co-hc ok but lamda reading was 1.051 2nd read 1.061, problem I have is limited funds and no access to a code reader so will be sorting this cave man style, I've already cleaned the maf few weeks ago as reduced performance kicked in with emission service required, it helped but didn't solve, was going to clean the etm (white label) also but after I get a gasket, I also noticed one day whilst looking for a mystery coolant leak (heater matrix in the end) around the turbo that the inlet pipe is not tightend properly so I imagine this is not helping, will be tightend before retest along with new fuel/air filters and engine cleaner thrashed through (oil/plug change also if funding permits), so now to the lamda's, all I can do here is test them to see if they're ok, I dont have a blow torch so I will haft to test on location, I've never done this so some guidence would be appreciated, I have a digi multimeter but not the best at using/understanding them, I can set it to 10a max unfused dc or 1000vdc 200ma max (which I imagine is what I'd be wanting) also dont know what dial setting I'd be needing or what pin off the sensor I would be jumping from, how much would it cost to just remove the sensors and hand them to a garage for proper testing? Next payday I will be retrieving any fault codes but wont be in time for the retest, it would make life alot easier but not an option unfortunately, thanks in advance for any info/advise given and will happily give a tin or 10 (on next payday) if I get her through, thanks again. Jim

draser · Post by **draser** » 07 Jan 2015, 17:27

What limits are they looking for?

belskee · Post by **belskee** » 08 Jan 2015, 03:52

0.960-1.040 so not a huge amount to be fair, little more than engine cleaner will fix I think though

draser · Post by **draser** » 09 Jan 2015, 17:51

I think you're right. Looks like you're running lean and I'd look for air leaks and some strong fuel injector cleaner. Combustion seems to be okay based on your nox results. My bet is on dirty injectors.

belskee · Post by **belskee** » 10 Jan 2015, 17:23

Well to update I changed fuel filter today (was filth) then ran some injector cleaner through, massive improvement on idle and response, she had an odd rattle for a while thats not rythmic (sounds random like something metallic tinging around inside) the work today seems to have helped somewhat with this, still there but half a bad, only rattles on idle and on load upto 2-2500 revs ish, also noticed today that if I rev quickly without load it rattles but I can reach the same revs gently with no rattle, could this be the etm I wonder? Anyhow I took her out for a spin hard in 2nd and around 3000 rpm it went into reduced performance again, the engine managment came on and 2 messages, engine system service required and engine system service urgent, no emission service message this time though, I reset and opened up 2nd gear again but gently and happily got to 4000 rpm no issues, I got the multimeter out after reading up on testing the mass air flow sensor with pins in the number 2 and 4 wires at the connection point, I tested at 20v setting and got a reading of around 9v but it didn't increase or decrease inline with the engine being reved, just stayed at 9 odd volts so am I right in thinking new maf needed here? I really would like to clean the etm before the emission retest but I cant find the gasket online anywhere, guess its only available from volvo? Have no idea how much they cost but is it possible to reuse the gasket for now then replace new later? I read somewhere (I think on here) about contactless sensors for the etm and was thinking about trying to fit one instead of replacing the whole unit, im good with soldering so confident I could do the job, if this is worth doing and the gasket can be reused I might consider cleaning the etm for the test then replacing the gasket when I get around to the contactless sensor install

belskee · Post by **belskee** » 10 Jan 2015, 17:33

To be more clear about the rattle when its cold it rattles on idle and when reved to 2-500 but warmed up a bit it stops at idle but can still hear it with revs load or no load doesn't seem to make a difference, clutch in out no change either, find it odd though that no rattle if reved gently

draser · Post by **draser** » 11 Jan 2015, 07:57

On the rattle - where is it coming from and did you check exhaust shields? MAF - pin 2 is battery voltage, signal pins are 5 (violet wire) and 3 (green w/white stripe) wire. You could reuse the gasket if you remove w/out distorsion then apply a smear of liquid gasket both on gasket and metal. Everything has to be clean.

belskee · Post by **belskee** » 11 Jan 2015, 17:08

Ah so I was checking the wrong pins good to know, the rattle doesn't seem to be from any of the shields, I proded around with the end of a hammer to apply pressure to different parts of all the heat shields and heard no changes, it sounds loudest from the front of the engine and it seems just as loud if im listening from the top or bottom, I attempted to test the lamda's today (not sure if did correctly) warmed her up and unpluged the the pre cat sensor, with the multimeter set to milli volts I earthed the negative to the engine and positive to the pin that determined to be for the black wire (top right pin in the connector), I did get a reading at idle from .1 which fluctuated up and down highest was .7 and I think briefly at .8 but averaged mostly between .2-.6, I then checked the post cat sensor using 2v setting again negative earthed to the engine and positive to the pin inline with the black wire but got no reading (briefly got 0.01) have I done this right? As im assuming here the front o2 is good and the rear 02 is dud, will retest the maf with the pins you're telling me tomorrow

draser · Post by **draser** » 11 Jan 2015, 18:22

How many wires on front o2 sensor?

Post by **abscate** » 12 Jan 2015, 04:37

Jim, please break your posts into sentences with punctuation per Forum rules, and Good luck getting it through MOT!