Probleme sonda lambda (O2)

[Picu]

Salut

La C3 1.4i, an 2003, am 2 nelamuriri, poate niste sfaturi ar ajuta:
1. La prima pornire a zilei, sau cand motorul e rece, se aude ca un aspirator, adica are pe motor un motoras electric care baga aer in moto. E normal? Ce rol are ?
2. Lipsa puterela turatie joasa: in urma testului imi da - code P0420 may mean that one or more of the following has happened: Leaded fuel was used where unleaded was called for A damaged or failed oxygen sensor (HO2S) Downstream oxygen sensor (HO2S) wiring damaged or connected improperly The engine coolant temperature sensor is not working properly Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe Retarded spark timing The oxygen sensors in front and behind the converter are reporting too similar of readings.

Cu alte cuvinte, pentru speta 2....cum identific problema ? Are 2 senzori de oxigen ? Cum imi dau seama care e ? Poate fi catalizatorul infundat ? Cum imi dau seama?

In speranta unor sfaturi, multumesc anticipat.

[yary]

Salut, ai rezolvat problema? Ce senzor a fost de vina?Am si eu o problema de genu la un xsara 1.6, la schimbarea vitezei tremura... iar la test mi-a dat tot ceva de genul paremi-se.
Mersi!

[George RTL]

posibil si catalizator,dar mai probabil sondele lambda.