MOT fail again please help

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fix it

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failed my MOT today on the emissions being too high.
went there with a very small miss-fire, not too bad at all.
failed on the emissions being way too high. 2500-3000 something.
then i went to go see the local landrover specialist and he put a heat reader on each exhaust pipe.
two were off the scale.
driven the car about 90miles today with no overheating and it was pulling well. what could be causing this on only two cylinders?
i have new bosh leads and ngk plugs.
it is a p38 4.0 8v 1996.
 
O2 or lamda sensors would do this I think, could be wrong, they are not expensive and easy to change.
If you dont have the equipment yourself, its worth paying the 80 quid or so to have a dealer plug into it and get a definite answer - saves the hassle
of changing too many things
 
Thanks mate but would that not make all the cylinders run too rich or lean.
How ever since i had the car I’ve always kept the same ht lead order the last owner had them in.
thinking about it he had it compression tested and shown low compression so maybe he just throw them back on in any order.
IV now changed them to this if it makes sense.
 

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hi mate had this problem before the trouble with a mot is that if they fail for emmisions they cant tell what infact is the problem always go for the cheapest option which we did the lamba sensor a mot retry failed again ..... it turnerd out to be the catalic converter ..im afraid missfires and especialy back fire will ruin a catalic converter so your choices are lamba air flow meter verybad air filters and worst of all catalic converter hope this is of help joe
 
Are the cylinders that were low compression next to one another and the missfire there if so probably head gasket blown between two cylinders.
 
sorry should have said just replaced head gaskets.
along with new water pump, thromstat, rad.
 
thanks for all the replys after i changed the ht lead order it seems to be running alot smother and the missfire has gone.
Im now booked in for just a emission test on saturday.
 
lol now thats funny so your admiting you got he ht leads the wrong way round well done for honesty sorry for laughing ....ps never rush do one at a time its so easy to forget!
 
defender300td1 said:
lol now thats funny so your admiting you got he ht leads the wrong way round well done for honesty sorry for laughing ....ps never rush do one at a time its so easy to forget!
Click to expand...

No im not admiting to nothing:eek:. i kept them in the same order thay were in when i got the car. But when i brought it it had hg fail so maybe the last owner put the back in the wrong order.
 
after reading your first thread again i did not see that you had just bought the car my fault for assuming just that you had bought new leads ect hope all is well and you get it passed
 
fix it said:
failed my MOT today on the emissions being too high.
went there with a very small miss-fire, not too bad at all.
failed on the emissions being way too high. 2500-3000 something.
then i went to go see the local landrover specialist and he put a heat reader on each exhaust pipe.
two were off the scale.
driven the car about 90miles today with no overheating and it was pulling well. what could be causing this on only two cylinders?
i have new bosh leads and ngk plugs.
it is a p38 4.0 8v 1996.
Click to expand...

Did it pass the re-test?
 
nope still got 1500 hyrdro carbons. its with the local landy guy now for dianostics. but i have phoned another local guy that brakes p38's for a living to see what he will other me. Im starting to have had enough of it now.
 
I have with good experience used octane booster like this one: Millers Oils Petrol Power Ecomax

MOT guys saying very clean car, also used Millers on diesels but another one of course, plus the car treated seams to run so much smoother, maybe it's just in my imagination but use it now and then and always double dose & good high rev run before an MOT, never failed on emissions, knock-knock, wood that is:)
 
thanks again for all the comment all very helpful.
Just got off the phone with the local landy guy and he said the ecu had one stored fault and one lambda sensor wasnt working properly so he reset the ecu and sorted the sensor. So hopefully it should pass an mot later this week.
 
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