Hi,
My car is eating O2 sensors, i am about to fit the 4th one in about 6/7 weeks. When it is 1st fitted it works fine, drive about 50 miles to work on a Sunday afternoon the AFR shows all the right readings, park the car up until Friday afternoon, as soon as i strike her up the AFR shows 'lean' and when i drive off the display shows nothing no matter what on/off boost or cruise I have checked the AFR and there are no faults with it. The sensors i am fitting have all been of the 'universal' type and NOT OE.
Any help/ideas would be a greatly appreciated. Thanx, Steve.

 

Maybe the sensors aren't too good?

If you can justify the cost, get an Innovate LC-1 wideband system. It can simulate the narrow band output of the stock oxygen sensor plus you can accurately measure and log your AFRs with a computer.

 

Has this all happened since fitting the AFR gauge?
Where does it get its O2 signal signal from?

Does the Innovate allow a sim narrow band signal for the ECU AND a wideband signal at the same time?

nick

 

No, it all started after the MOT, it failed on emmisions so i changed sensor and it passed no probs, the rest is history. Well baffled

 

Butty, yes the innovate can output a simulated narrowband signal, a wideband signal and a digital signal via serial cable at the same time.

b13bat, could the 02 sensor location also be the problem? I know on 97+ WRX, it was moved from the headers to the downpipe to increase 02 sensor lifetime. Also have you checked whether the 02 sensor heater circuit is ok? An unheated 02 sensor will get fouled quickly.

 

saiklon, thanx for that, i was wondering whether to try the sensor in the downpipe rather than the header, will try it tomorrow and see how it goes, and yes the heater curcit seems ok ie it is putting out 12v.

 

What symptoms are you getting once they fail?

 

Slightly uneven idle and no reading on the AFR guage

 

sounds like my problem too .but am yet to replace the lambda sensor .been told the universal ones are crap ??

already done the maf and that cured half the problem .

been told too check all fuses also

 

OK have relocated the lambda in the downpipe and blanked of the hole in the manifold/header. Test run as per usual all seems well
Has anyone got any comments/problems in relation to having the O2 sensor in the downpipe instead of the manifold/headers??

 

Thanx all, problem solved me thinks, sensor now located in top of down pipe, AFR guage is now more stable too .

Any ideas why

 

The O2 sensor gets much hotter in the headers than in the downpipe. And since it's a heated O2 sensor, the extra heat isn't helping it any.

Glad you sorted out your issue.