1.8 mk2 mot fail on high emissions.

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1.8 mk2 mot fail on high emissions.

Postby dubwiser » Fri Jan 30, 2015 10:47 pm

Hi all ,

Looking for some help I have a 99 mk2 1.8 that I though ran a bit rich. It has a k&n typhoon kit on it, Have just serviced it and it had sooty plugs.

The car went for a mot today and the co2 and lambda were high. I have looked and it has a four plug lambda .

Blue - not much V
white - not much V
black - 14v
black - 0.31v when you rev the car there is no change in V until you let off and it goes open circuit and back to 0.030v

Can anyone confirm the wiring for the sensor? Heater, siginal ect. From what I can see the white/blue should be the siginal not the black (they are heater)




Finally if the sensor is goosed has anyone used the universal sensors that you wire your self?

Thanks

Ps. I have now reaserched the sensors a bit more and all tests have to be tested when the exhaust is hot as the sensor works at 600℃ and the blue wire is the siginal.

I will check tomorrow when I can test it.

Craig
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Re: 1.8 mk2 mot fail on high emissions.

Postby sclements » Fri Jan 30, 2015 11:12 pm

I have cat and sensors from a 1.6 2002 here for sale but have no idea if they will fit yours.

If you find out get back to me.

Scott
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Re: 1.8 mk2 mot fail on high emissions.

Postby sclements » Fri Jan 30, 2015 11:12 pm

.
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Re: 1.8 mk2 mot fail on high emissions.

Postby dubwiser » Fri Jan 30, 2015 11:23 pm

Thanks but I am 99% sure they won't fit. Thanks
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Re: 1.8 mk2 mot fail on high emissions.

Postby drumtochty » Sat Jan 31, 2015 12:45 am

The cat would make the CO go over the MOT figure buy not give black plugs.

That is what happened on mine and a change sorted it.

The damage was caused by a faulty coil pack putting neat fuel into the cat.

So that tends towards the sensor.

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Re: 1.8 mk2 mot fail on high emissions.

Postby dubwiser » Sun Feb 01, 2015 2:47 pm

Ok, I have pulled the sensor out and tested with a blow torch. It rises and falls as it should . 0v all the way up to 0.99v.

I have then refitted it to the car and measured the voltage. On idle the voltage is rising and falling it goes from 0v-0.9 and back down continually. If you rev the car it shoots up to 0.9v

My understanding is a healthy sensor should sit about 0.4v on idle and rise to 0.9v when revved, then to 0v when let off and finally back to 0.4v ish when returned to idle.

It would all point to a faulty sensor but can anyone confirm?


Craig
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Re: 1.8 mk2 mot fail on high emissions.

Postby drumtochty » Sun Feb 01, 2015 3:42 pm

Looks like one of these from MX5 parts is needed.

Prior to that check for intake or exhaust leaks and check the air mass sensor is clean.

http://www.mx5parts.co.uk/oxygen-sensor ... -3410.html
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Re: 1.8 mk2 mot fail on high emissions.

Postby dubwiser » Sun Feb 01, 2015 5:59 pm

Found really good link on lambda sensors and confirmed mine is ok, this is a great link with lots of good info.

http://mr2.com/TEXT/O2_Sensor.html

Pulled the plugs out 1week old and they are burning clean. Checked for air and exhaust leaks and found none. Checked and cleaned the MAF. Then stumbled across this boat on mx5 nuts.


"A bit of air mixed with the exhaust gases would give a lean reading like that. I've heard of people who get that because they have twin exit exhausts and pulsations suck air in through one pipe and contaminate the reading from the other. Sticking a rag into the second outlet fixed the problem".

And my car has the twin back box with a exit each side :evil:

Will get it booked in and try again with a rag up one exhaust and see what happens!.Will update next week.

Craig
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Re: 1.8 mk2 mot fail on high emissions.

Postby drumtochty » Sun Feb 01, 2015 8:04 pm

The wet rag on one outlet works somtimes, let's hope so!

Ok another few Mk2 specifics.

What is the battery voltage at idle and say 1,500 rpm.

Are the cabin drains clear to the bottom on both sides they are behind the seatbelt towers.

Lift the passenger side carpet. Basically where the passengers feet would be on the firewall, there is the ECU behind a cover held on by security bolts that have to be dremmeled off.

Is there any dampness or sign of water in that area like rust on the ECU connectors.

High lambda as you are aware is due to a weak mixture, it is possible that a tiny crack or hole in the exhaust between the cylinderhead and including the weld on the Cat is at fault but is not blowing.

You have a diode to check the ECU for faults I assume, what did that advise.

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Re: 1.8 mk2 mot fail on high emissions.

Postby dubwiser » Sun Feb 01, 2015 9:56 pm

I have not Checked the ecu as I cannot find any info on mk2 just mk1 . Is it the same?

Brand new battery, and inside is dry. I have seen a post where the manifold gasket was leaking.


Will check tomorrow
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Re: 1.8 mk2 mot fail on high emissions.

Postby drumtochty » Sun Feb 01, 2015 10:30 pm

The Mk1 and Mk2 have the ecu in the same place.

Are you saying that you have lifted the passanger carpet and the floor underneath was dry.

Touching the carpet and finding it dry is not an indication, lift it up as it is water proof.

What readings did you get from the light emmitting diode test.

You need to do that.

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Re: 1.8 mk2 mot fail on high emissions.

Postby dubwiser » Sun Feb 01, 2015 10:46 pm

Can you please confirm the pins to use for the led test.

Thanks
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Re: 1.8 mk2 mot fail on high emissions.

Postby drumtochty » Mon Feb 02, 2015 11:03 am

http://www.mazda-madness.co.uk/2010/03/ ... the-eunos/

They are the same on all Mk1 and Mk2 cars
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Re: 1.8 mk2 mot fail on high emissions.

Postby dubwiser » Mon Feb 02, 2015 7:17 pm

Thanks for the link it is all a bit confusing. The codes I get are 10 and 11.

I cannot find 11 anywhere. But I did disconnect the MAF yestarday while testing for lambda changes.

I have a video of the codes so think I will erase them and 're read tomorrow.

Craig
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Re: 1.8 mk2 mot fail on high emissions.

Postby drumtochty » Mon Feb 02, 2015 10:15 pm

You are not the first person to report an 11 flash code!!!!!!!!!!!!!

As you are aware both battery terminals disconneted and hold the foot brake down for a while a few times to get rid of any small voltage present in the ecu area.

Then as you say do the reading again.

I have just spent another three days not fixing my Suzuki Jeep vacuum hub system.
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Re: 1.8 mk2 mot fail on high emissions.

Postby dubwiser » Wed Feb 04, 2015 10:49 pm

Checked for fault codes after reset. No faults. Redex and a kicking and the co2 readings are a lot better but the lambda is still high.

Managed a friendly pass but still can't work out what's amiss. MOT tester says replace the Lambda sensor or the cat. I would like to be a bit more scientific than that.

The cat looks new ish so may just be a cheep snide one. Has anyone any experience of the typhoon air filter kit causing issues.

If you rev towards the red line there is a puff of black smoke.

Craig
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Re: 1.8 mk2 mot fail on high emissions.

Postby drumtochty » Wed Feb 04, 2015 11:07 pm

If the cat was away it would fail on emissions in my opion.

With regards to the puff of smoke there is some late MK1 ad early Mk2 1.8 cars that suffer from sticking oil control rings.

Just enjoy the car this summer and worry about it next year is my best advice.

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Re: 1.8 mk2 mot fail on high emissions.

Postby dubwiser » Thu Feb 05, 2015 9:14 am

Yeah thanks for all the help. A least all my welding was up to scratch. The mot tester was very impressed :lol:

Cheers

Craig
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Re: 1.8 mk2 mot fail on high emissions.

Postby Richardn » Thu Feb 05, 2015 6:14 pm

The replacement cats sold cheap at the moment are lucky to last a year

You can buy a MK1 cat for £70 so it cannot have much precious metal in it
Mk3 2.0 sport & Mk1 California 217/300
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