More on the EGR Bypass Valve....Modify or Leave alone

Jules · 4th December 2007, 10:05

Quote from Rincewind:
"Then for OBD purposes, we have to fail the system or by-pass it to see if the system falls within the OBD limit requirements in this instance, it's fully open like a by-pass system would be."

There are a few definitions I have to point out here:
A bypass system cannot be the same as an EGR held open.
As I understand it, a bypass "tube" completely blocks off any possibility of exhausted turbo gases re-entering the combustion

I'd like to see the emission figures done with the bypass "tube" fitted instead of the figures given above for an EGR valve held open. I'm sure that 457% NOx figure would be no where near as bad.

Finally how many EGR valves actually get cleaned in the car's lifetime by their owners or garages do you think?
Probably less than 10 %

So the 90% of clogged up (and many stuck open) EGR valves being driven
round the country are actually polluting our planet by that 457% NOx figure!!!
It can be concluded then that the device is best removed

Oh and well said Zeb in post # 16

4th December 2007, 10:05	#11
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	Quote from Rincewind: "Then for OBD purposes, we have to fail the system or by-pass it to see if the system falls within the OBD limit requirements in this instance, it's fully open like a by-pass system would be." There are a few definitions I have to point out here: A bypass system cannot be the same as an EGR held open. As I understand it, a bypass "tube" completely blocks off any possibility of exhausted turbo gases re-entering the combustion I'd like to see the emission figures done with the bypass "tube" fitted instead of the figures given above for an EGR valve held open. I'm sure that 457% NOx figure would be no where near as bad. Finally how many EGR valves actually get cleaned in the car's lifetime by their owners or garages do you think? Probably less than 10 % So the 90% of clogged up (and many stuck open) EGR valves being driven round the country are actually polluting our planet by that 457% NOx figure!!! It can be concluded then that the device is best removed Oh and well said Zeb in post # 16 __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block