Joe82

High HC emission problem

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Hi there.

I have a Ford Fiesta 1.6 16V 100HP car, year 2003. On the emission test the HC value became high, more than 400. The consumption of the car is a little bit high. I made some tests with the Forscan program and here are the results on the attached images.

If I open the engine bay there is a hissing sound from the right side of the bay, maybe the brake booster. When inside of the car I push the brake pedal it has a hissing sound.

Sometimes the short term fuel trim value is -17% or +17%

Any idea? 🤔

 

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Fust.png

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I'd say compression test the engine to be sure the fuel is not just getting pushed out past a sticky valve without being burnt off properly especially if consumtion has gone up. If it passes, could be injector leaking into the chamber.

Could get away with new plugs, leads and coil for a stronger spark to burn off fuel better.

Hiss noise is strange. Brake performance and different? Pass MOT check?

 

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It has 2 months old NGK Laser Platinum plugs. Th car runs very good.

Sometimes, rare, when I want to start the engine it won't start until I push the gas pedal.

The brake works great, passed the MOT check.

The MAF value is like 82mg, it should be more, like 400mg?

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I cleaned the MAF sensor and made some new tests, but it seems to be the same.

newtest6.png

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33 minutes ago, JONATHAN_11_80 said:

What's the long term fuel trim value?

In the Forscan program there is only short term fuel trim. I could not find the long term fuel trim.

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Your lambda value has only just scraped through as well.  Which could indicate an air leak somewhere and would make sense with the hissing you're hearing.  The PCM might be trying to compensate for this by adding more fuel.  With such a high CO level I wouldn't be surprised if the cat is knackered by now though.

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2 hours ago, TomsFocus said:

Your lambda value has only just scraped through as well.  Which could indicate an air leak somewhere and would make sense with the hissing you're hearing.  The PCM might be trying to compensate for this by adding more fuel.  With such a high CO level I wouldn't be surprised if the cat is knackered by now though.

The cat or maybe only the OS2?

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1 minute ago, Joe82 said:

The cat or maybe only the OS2?

I'd suggest the cat with such a high CO reading, they get damaged by unburnt fuel passing through them.  You need to fix the fault causing the excess fuel (and HCs) before you can decide whether there's an issue with the cat though.

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24 minutes ago, TomsFocus said:

I'd suggest the cat with such a high CO reading, they get damaged by unburnt fuel passing through them.  You need to fix the fault causing the excess fuel (and HCs) before you can decide whether there's an issue with the cat though.

I see. I will try to localize the air leak. I hope the cat is still alive because it is an expensive stuff. 🙄

Thanks for your advises.

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I was at the service and they said that the hissing noise from the engine compartment is normal, it is the air that enters in the engine or something like that.

I made a PCM adaption reset and here are some results.

Results.png

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If I put my hand on the throttle body, the engine dies immediately.

If there would be a vacuum leak the engine should work on?

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