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Nilla

Exhaust values

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My Yaris 00, 350000 km is performing very well and i´d like to keep it for a couple of more years. But at the latest inspection I had very high exhaust values. The codes showing is P0171 and P0420. I changed the cat two years ago (not original), MAF is cleaned, lambdas are a couple of years old. The spark plugs tell me it´s poor mixture. Something more, I don´t remember what, also indicates poor mixture. One can sense a little petrol fragrance. Anybody who has an idea about what it might be?

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42 minutes ago, Nilla said:

My Yaris 00, 350000 km is performing very well and i´d like to keep it for a couple of more years. But at the latest inspection I had very high exhaust values. The codes showing is P0171 and P0420. I changed the cat two years ago (not original), MAF is cleaned, lambdas are a couple of years old. The spark plugs tell me it´s poor mixture. Something more, I don´t remember what, also indicates poor mixture. One can sense a little petrol fragrance. Anybody who has an idea about what it might be?

Could be the mixture is too rich, is the engine consuming a lot of Oil?

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No, I don´t fill upp very much extra outside service. Maybe once a year. The spark plugs shows poor according to my mechanic...

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11 hours ago, Bernard Foy said:

Could be the mixture is too rich, is the engine consuming a lot of oil?

No, I don´t fill upp very much extra outside service. Maybe once a year. The spark plugs shows poor according to my mechanic...

 

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P0171 is a lean code, i would suspect a vacuum leak, do a visual inspection of the air intake and all vacuum hoses, ideally you need to do a smoke test, if not use some carb cleaner and spray around a few areas with the engine running it the engine changes sound it has a vacuum leak

p0420 is a symptom of a lean code but it could also be the cause, what make where the lambda sensors anything except Bosch,Denso or NTK usually die with in 12-18 months, cheap sensors are a false economy

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9 minutes ago, flash22 said:

P0171 is a lean code, i would suspect a vacuum leak, do a visual inspection of the air intake and all vacuum hoses, ideally you need to do a smoke test, if not use some carb cleaner and spray around a few areas with the engine running it the engine changes sound it has a vacuum leak

p0420 is a symptom of a lean code but it could also be the cause, what make where the lambda sensors anything except Bosch,Denso or NTK usually die with in 12-18 months, cheap sensors are a false economy

What´s a smoke test? I forgot to mention that we covered the exhaust pipe and it said poff, as it was supposed to do.. But I guess that it´s not what you meant..:)?!

According to the computor my front lambda starts working after a while but I guess that´s not the point either...?! I´m not so skilled at this but I´ll forward this to my mechanics.

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a smoke tester is a machine you attach to the intake what pumps smoke into the intake and vacuum systems if there are any leaks it will show them

 

 

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We made a smoke test and it was only a small amount leaking by the MAF and the mechanic suggested to have it changed. Do you think that would be a reasonable action? (motor is performing very well, code and spark plugs saying lean mixture and exhaust values saying high..)

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On 6/23/2020 at 11:14 AM, flash22 said:

P0171 is a lean code, i would suspect a vacuum leak, do a visual inspection of the air intake and all vacuum hoses, ideally you need to do a smoke test, if not use some carb cleaner and spray around a few areas with the engine running it the engine changes sound it has a vacuum leak

p0420 is a symptom of a lean code but it could also be the cause, what make where the lambda sensors anything except Bosch,Denso or NTK usually die with in 12-18 months, cheap sensors are a false economy

CO: 0.7(0.5), CO 2500v: 0.7 (0.3)

HC: 580(200)

Lambda: ok 1.02 (0.97-1.03) 

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