Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: wayneywoo on 05 April 2008, 17:47:42

Title: 4 wire Oxygen Sensor failure? '99 2.0ltr
Post by: wayneywoo on 05 April 2008, 17:47:42
Guys,

Just replaced the front pipe/cat and with the old one blowing, the only code I had flash up was for the cam sensor.

Fitted the new pipe, swapped the O2 sensor over, plugged it in and now the EML won't go out and I get codes 0130 and 0135 flash out as well as 0340 for the cam sensor.

I find it hard to accept that the sensor was working but now isnt.  Would both the heater and O2 element fail at the same time or could this be an open circuit instead?  Is there a way to check the O2 sensor?

I had a two wire sensor on my old Rover and to check it was working, I just plugged a multimeter on to the two wires and saw the reading on the meter flip high then low.  Which two wires heat the sensor and which two give the O2 reading?

Also, another thought, do error codes need removing?  This wasn't/isn't an issue with the cam sensor as sometimes the car started with the EML light stay out and when I checked for codes to flash out, I didn't get one.  It wasn't until the EML light came on that I would then, on the next start, get the code to flash out so I wondered if certain codes need clearing?

Phew, sorry for the length of post!

Thanks for any replies guys!

Wayne
Hemel Hempstead
Title: Re: 4 wire Oxygen Sensor failure? '99 2.0ltr
Post by: Marks DTM Calib on 05 April 2008, 18:36:28
Sounds like a classic cheap pattern cat fault.......which part of the exhaust was blowing, the flexi joint?
Title: Re: 4 wire Oxygen Sensor failure? '99 2.0ltr
Post by: wayneywoo on 05 April 2008, 19:41:36
Yeah, blowing at the flexi joint.
Title: Re: 4 wire Oxygen Sensor failure? '99 2.0ltr
Post by: ajb on 06 April 2008, 23:23:54
Why would a cheap cat through a code for heater element though?
Title: Re: 4 wire Oxygen Sensor failure? '99 2.0ltr
Post by: Marks DTM Calib on 07 April 2008, 08:25:20
Quote
Why would a cheap cat through a code for heater element though?


Because, one of the methods the ECU uses to determine if the heater is ok is that it monitors the switching speed of the sensor, if its low then an assumption is made that its not hot enough and hence a heater fault can be flagged.

Naff quality cats can affect the gas flow and result in the sensor not getting as hot.

Did you know you can get flexi repair sections for about 20-30 quid where you cut the old one out and clamp a replacement in.......