hello, i have a 95 Mondeo 2.5 v6 that has failed its mot on emissions being to high, my problem is i don't want to spend loads of money on changing cat converters as it has three of them, is there any way to test them??? also i don't know how to test the lambda sensors as there's two of them???... then there's the engine electrics could it be them??? i was told the lambdas were at 0.9 and the emissions were at 10% so they were sky high. but i cannot be sure of this as i had no print out.. is there anyway of testing???? thanks for any help you can give
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v6si
Why haven't you been given a fail sheet and emissions printout - it's a VOSA requirement?
Accepting your figures at face value; it's not the cats and if the oxygen sensors are running full rich at 0.9volts, then they are doing all that they can to lean-off the mixture.
10% CO is ridiculously high - so high that either there's a major fuelling error, or someone has been playing with the ECU settings....?
Get it plugged-in and the codes and data read.
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they started with the emitions and said they were to high so i said dont bother carrying on with the rest of the test and they didnt charge me. so thats probably why i didnt get a read out. my mate tried his snap-on tester in to the dash but it didnt work, just never came on... do i need a speical tester or should a local garage be able to test it?
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v6si
No MOT test starts with the emissions - there's a very tightly regulated procedure. So if the garage did an emission test - why? What's not being revealed here? Let's have the full story - from the beginning. Has this been "chipped?"
Most mid 'nineties Fords can be a bit tricky to access; but a Snap-on scanner should read these - in the hands of a competent user.
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i bought the car cheap knowing it had failed the test on a few things the emitions being the main reason. with the intention of fixing it, i found a couple of vacume pipes snapped so i changed them give it a service oil,plugs,filters etc. the previous owner was an old guy and its an estate so i dont think its been chipped but i could be wrong. i took it to the local garage after a gud thrash to clear it out, where my mate who`s got the snap-on tester works an asked him to put it on the emission test first, which he did but it didnt pass. and he said it might be the cat. when he pluged the tester in he said it should come on its own but nothing happened which i thought sounded a bit strange. does this sound right? thanks for your help so far
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v6
Right; now we have the full story, things are clearer. As said; 10% CO is a huge amount. Only a major fuelling error will show readings like that and comparatively few things can cause it.
If you can't get it read; check the air filter and the fuel pressure - it should be 29-35 lbf/sq" at idle. The coolant temp sensor should be c.3800 ohms at 80C; c.50,000 ohms at 15C. There should be c.0.7 volts on pin D of the MAF sensor and under 1 volt on pin 2 of the throttle sensor at idle.
Check that the DLC has an earth on pin 7; or use a separate power feed for the scanner.
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thanks for all your advice, as i`m a novice mechanic i`ll see if my mate will bring his tester and have another go with that. should the test`s be made engine running? e.g start with plugs off and test then or push pin into approprate leads when running? thanks again you`ve been very helpfull
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v6
All tested in normal running condition at idle. Backprobe the plugs with [0.6mm stainless?] MIG wire.
That's the data and tests - you may need somebody to do them for you.
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v6si No MOT test starts with the emissions - there's a very tightly regulated procedure.
The Government operated Mot centres here in N.Ireland all start with the emissions test.
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hi andy i new the emissions were high as i bought the car as an mot failiure cheap, so i asked them to check it before i had the mot. after they told me it was still to high i told them not to bother with the mot and took it back home but now i dont know how to solve the problem.
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AndyT
So they bring the car into the bay from the car-park and do the emissions test on a stone-cold engine/cat? Sounds a bit Irish to me?
VOSA specify doing it at the end to allow a minimum of 20-ish minutes running to heat the cat.
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Snipquote
It's not quite like that (Screwloose). Over here we have to use dedicated, fully computerised, Mot centres with typically 3 to 4 lanes, which can handle a couple of cars on each lane, plus a lane for HGVs etc.
You apply for a test date/time, which currently for me is a 5 week waiting time, and then drive to the centre at that time to get tested. First thing you see when you arrive, is a notice saying to have your vehicle at normal operating temperature. Vehicles are then emission tested at the test lane entrance.
Do the Government run Mot centres on the mainland not run the same way?
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The Testers Manual states the Emissions should be tested first on both Cat & non-Cat vehicles while still hot from the road;on a Cat vehicle only the high-idle test comes before the general emissions test.
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..and if they've been left outside in the car-park all day?
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I should have said "recommends"tested first but states tester must ensure that engine is fully warm.
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