Just been playing around with Datascan now that I have a working cable.

 

I have noticed that when cold the O2 sensor reads 15, this slowly drops to about 5 once the car is warm,

 

Sitting at idle it never jumps up and down like I see other people say it should.

 

Does this mean one or both are broken?

You need to alter your DataScan tool to display both O2 sensor outputs so you can compare.

My current Z has a failed sensor, with DS set to read both the output on one swings wildly with a few revs which is correct, the other sits still, can't remember at what value, but that means its dead or lazy. I've currently unplugged both to get a static ECU average value to get me by as in my case the car runs like crap with one dead sensor, but only during the warm up period.

I would say one of yours is on the way out from what you've said.

Take it your com port wasn't duff after all?

 

IIRC, the default O2 sensor reading is for the LHS, you have to call up the RHS sensor reading.

Edited November 8, 201411 yr by lonezedder

Yeah com port was ok, was a cheap crappy Chinese cable that was the problem.

 

Sent that back for a refund and got an ecutalk cable which works great.

 

I have the other rhs o2 sensor up on the data display, it constantly sits at about 25 as well.

 

Very annoying thing about it is, when my decats got fitted about 2 years ago I gave them brand new o2 sensors to fit, but they gave me them back saying they didn't have to fit them......and I just sold them for pennies on ebay.

 

I think when the car gets mapped in April/May after it's winter hibernation I shall get them to alter the map so that the o2 sensors are not used.

 

From what Noz says running the car with the sensors disconnected causes it to over-fuel a fair bit.

Yep, can be mapped to run without, but apparently a time consuming process. Running without does make the car run richer, but as a temporary situation it causes no problems, it seems some people have run without them plugged in for a long time without issue.

I do naff all miles in mine anyway, certainly not in winter, I'll be getting mine changed soon when I place an order from the US.