P0403 Question

Hi Guys,

Not sure if you've read my Fraser thread, but yeah .. I've got another issue now .... just can't win.

Came back to me car after work and started it up, and saw the check engine light on. Checked all fluids, drove fine with no issues, so got home and plugged up my OBC sensor and it read P0403.

Saw few threads about it here, so first thing I thought I'd try was reset ECU.
After doing this, the code seems to have gone and can't pick it up on my app no more.

Just wondering if its safe to keep driving like this, or would it be a ticking time bomb waiting to go off?

If it is the EGR valve, sooner or later it'll drop your car into limp mode.

I remember reading about some faulty EGR valves on the 550s, which turned out to not be faulty valves but faulty software. The fix from Nissan required that they replace the valve and update the software, but one dealer neglected to replace the EGR valve and they discovered that the problem was resolved anyway.

I'd be talking to your dealer about it. I'm sure there's several threads on here about it. Your car won't blow up, it'll just go slow. Nothing will get damaged.

Hi Tony,

Thanks for the quick response mate. Hoping it's not that.
I've got 3 months/100k warranty on the whole block, however getting it back up there and down + time off work, couldn't justify it.

Old.Tony said:

If it is the EGR valve, sooner or later it'll drop your car into limp mode.

I remember reading about some faulty EGR valves on the 550s, which turned out to not be faulty valves but faulty software. The fix from Nissan required that they replace the valve and update the software, but one dealer neglected to replace the EGR valve and they discovered that the problem was resolved anyway.

I'd be talking to your dealer about it. I'm sure there's several threads on here about it. Your car won't blow up, it'll just go slow. Nothing will get damaged.

Click to expand...

The software was a patch job. It's still a faulty valve but the patch just extended the parameters it faults out on. The temp fix was because the egr valve is a Bitch to do. Nissan say body off ect.

So it was both! Please don't mistake the expression on my face for 'surprise'.