# Renault Laguna II, Manifold Pressure Sensor 1.9 dci & 1.8 16v



## sashko (Jan 25, 2008)

I have had increased consumption problem with my Laguna II, 2002, 1.8 16V that turned out to be a problem with Manifold Pressure sensor and Lambda probe. I bought the parts thru a dealer and have them installed in the garage. After replacement no improvements. The mechanic suggested that the Manifold sensor is not the proper one for my model. The package of the spare part had a label in which Laguna 1.9dci is written, along with some Nissan 1.2 and 1.4 engines. The dealer is convincing me that the same pressure sensor is for 1.8 gasoline engine, and the reason why this model is not on the label is because the manufacturer didn't have enough space to put all models on it. Is he right, i.e. same pressure sensor goes on dci model and 1.8 which means the problem is somewhere else or he is just a funny man? btw, the diagnostics showed problem with pressure sensor and lambda probe. What else could be the problem? Please help....!!!


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## qldit (Mar 26, 2007)

Good Morning sashko, Obviously this problem has been determined by code reading, but I really don't consider the codes to be all that accurate, just assistive.

If we consider that the engine parameters are referenced to a preprogrammed kind of expectation under normal running conditions then an oddity may give an error.

Very often these errors are caused by other conditions such as leaking manifolds or improper flow of gases through the system from the air intake to the exhaust outflow.

Typically a restricted air intake or a restricted exhaust system can also give errors that appear odd, simply by their unexpected effect.

It may be worth considering the possibilities that can cause excessive fuel consumption (like air in or exhaust out) from a basic aspect before getting too involved with other things.

A leaking intake manifold may also upset the system, remembering that the computer is trying to inject fuel to reduce oxygen presence in the exhaust flow, so any intake manifold leakage could have odd effect.

This can often be checked with a butane or similar gas torch (with no flame!) set for good gaseous flow and directing the gaseous flow around areas of the intake manifold while the engine is idling. A change in engine characteristics while doing this can suggest a manifold leakage problem.
The reason this has effect is because it introduces a different kind of input for the engine and combustion.

Vacuum system leakage may also have effect.

Sorry can't comment on correct part identification, but I hate changing anything on these kinds of machines unless I can verify conclusivley that they are crook and then prefer to use identical component replacement parts.

Others will have different ideas.

Cheers, qldit.


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## sashko (Jan 25, 2008)

Thanks a lot qldit. I really appreciate your effort.
I will defenitely point out this suggestion to my mechanic and hopefully he'll manage to find the cause of this problem.

Best regards and Cheers...
Sashko


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