Toolman22

Hi,

I have a Audi 100 (1991-C4) 2.3E 5 Cyl 98 KW with 180.000 km.

The following is occurring with my car:
1- Very rough idle rpm with cold engine (nearly stalling)
2- High consumption of Petrol

So I asked my dealer to replace:
1- Distributor cap + rotor + gasket
2- Spark plug cable 's (I allready have installed 5 new spark plugs Bosch Super 4 and threw the OEM NGK spark plugs away)
3- o2 Sensors (two)

The dealer is charging € 148 for one o2 sensor. He told me that the second o2 sensor doesn 't need to be replaced, because the second sensor basically monitors the condition of the catalytic converter.

What should I do? Insist that he should also change the second o2 sensor or just let them change the first o2 sensor. If it is true what he told me, then it seems to me that it makes no sense to replace the second o2 sensor, but I 'm no mechanic, so I am asking advice.

Thank you in advance

Muhammad

I'm not very familiar with the I5 engine, but if it is after the cat, I've heard that those have a much longer life than the O2 on the exhaust header....

Toolman22

That 's what the dealer told me. He told me that it was after the cat and is only monitoring the cat 's condition. But should I replace the second o2 sensor with the one on the exhaust header?

QCRAZY

...I've never seen one with 2 sensors. All the 2.3L engines that I've seen have only ONE O2 sensor that is located IN the cat.

You may have a different set-up in the UK. But I've only ever seen one sensor.

HTH!!