Did Etest, last july passed PERFECT

did one yesterday for plate renewal, failed NOx (435 limit, got 690) everything else is like WAY low and awesome..

Now the EGR, Its digital, I unplugged it and drove home, car drove same as it does now, no change, Im thinkin its not working, what usually happens to this expensive egr valves lol?

I got a chance to get free one from g/f's uncle so Im putting it on and retesting, but i got no Engine codes, and like I said plugged in or not no change, car runs good all the time so Idk, no stalling or hesitation or surging.

Anyone shed any light

(1992 RS 3.1 Auto)

 

You shouldn't notice any drivability difference if the egr is working correctly. If you unplug it, it won't feel any different than if it were working.

Since you can get one, I would stick it on since you don't have the stuff to actually make sure it is working properly.

You can alos try installing a new O2 sensor. You'd be surprised how much an O2 sensor affects NOx. There have ben many, many cars that I have repaired for NOx failures that all it took was a new O2 sensor.

 

Ya, o2 can cause like double the limit? Hmm, Ill try EGR and retest, then Ill see whats up, and do o2 if needed!

Everything else is so low though, like HC and CO are next to nothing, perfect readings for my 327,000km 3.1 lol

But the nox, and it was PERFECT last year...

Where is the o2 in this thing (used to my 350 lol :$)

 

Well damn

Put my buddys newish Egr on, went from 690 to 1756!!! Im thinking that this thing is not even working now, Im gunna trace wires, limits 450, thats all I changed, before it was 690, ALL i changed was EGR and it jumped to 1756, Any ideas

 

I had similar numbers turned out to be the O2