[Bitter]

The 1ZZ (your engine if it's a plastic intake manifold) has a common issue with the intake manifold rubber gaskets leaking, usually an engine light will set with a lean code but not always. Typical symptoms besides engine light are poor idle and poor running when cold that improves as the engine warms up. The gaskets are fairly easy to change with a lot of Youtube videos showing how as well as the gaskets being pretty inexpensive and easy to obtain from just about any parts store.

 

[Bitter]

The gaskets fail more with age than miles or driving habits, the rubber compresses and becomes hard then fails to seal between the plastic manifold and the metal head since they expand at different rates when heating or cooling. At almost 23 years old I'd really suspect that those gaskets are leaking air into the engine, whether or not that your problem I cannot say. If you have access to a scan tool you could try to see what fuel trims are, if the trims are high positive values then there's like a vacuum leak and that's the most common source on the 1ZZ.

 

[Bitter]

Sorry about the rubber gaskets you told me are on the intake manifold, are they between the manifold and the cylinder head?
Best Regards

Correct!

Gasket looks like that but may be a different color such as green or blue.

 

[Bitter]

Ok, maybe i can get it in Toyota Portugal, is a litle expensive, but not to much in rubber materials

It's the same gasket that almost every 1ZZ uses so it should be readily available almost anywhere but I can't comment on the cost.

 

[Bitter]

Absolutely, in the case of the gasket if it's bad even a cheap part will be better but may not last as long as a good part.

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