EGR Valves

[bwlknsn91]

I have read in a couple threads that the Canadian EGR valve is much better then the standard replacement for the US. I'm just wondering what about it makes it different/better than another. I am having idling issues so looking into every possible problem and solution. Thanks!

 

[njaremka]

the canadian version has connections to circulate coolant through the valve body, and a vent hose. these two additions were made to help alleviate condensation and corrosion, and to add life to the egr valve.

this is the valve:
http://www.rockauto.com/catalog/moreinfo.php?pk=1515368

 

[CHIQLES]

plus its aluminum not cast iron valve. It seals better and travels smoother.

 

[bwlknsn91]

the canadian version has connections to circulate coolant through the valve body, and a vent hose. these two additions were made to help alleviate condensation and corrosion, and to add life to the egr valve.

this is the valve:
http://www.rockauto.com/catalog/moreinfo.php?pk=1515368

So I'm other words, replacing the stock EGR to the Canadian version wouldn't effect idle but just increase the life of the EGR?

 

[njaremka]

EGR doesn't work at idle anyway, so... the EGR valve is only supposed to operate during cruising conditions. however, as it gets funked up, it will stick open and make your engine stumble during idle.

as an aside, i replaced my original EGR valve with an oem original valve at 60,000 miles, then replaced with an oem revised valve at about 80,000 miles, then with canadian valve at about 125,000 miles. the canadian valve has been running smoothly now for the past 3 years, and 75,000+ miles.

 

[bwlknsn91]

EGR doesn't work at idle anyway, so... the EGR valve is only supposed to operate during cruising conditions. however, as it gets funked up, it will stick open and make your engine stumble during idle.

as an aside, i replaced my original EGR valve with an oem original valve at 60,000 miles, then replaced with an oem revised valve at about 80,000 miles, then with canadian valve at about 125,000 miles. the canadian valve has been running smoothly now for the past 3 years, and 75,000+ miles.

Well my main problem is when I am coming to a stop or to slow down in general and shift into neutral, the RPM's plummet real low almost killing the engine. But if I have my A/C on, this problem disappears along with the CEL that pops up if I don't have the A/C running.

 

[njaremka]

if you get a CEL, have you had the code pulled? if the EGR opens during cruise, then gets stuck, when you drop to idle the engine will stumble. if it happens more than once, it should throw a code.

 

[bwlknsn91]

if you get a CEL, have you had the code pulled? if the EGR opens during cruise, then gets stuck, when you drop to idle the engine will stumble. if it happens more than once, it should throw a code.

I've cleaned it about 2 months ago but I guess it's possible it just went bad since I have almost 100k miles on my car. And everytime I've had a CEL it's been the p0171 code, but if the A/C is on it disappears.

 

[njaremka]

i had my first valve completely apart, cleaned every little bit of it, and it didn't do a lick of good. ended up replacing it anyway.

the idle boost function in the AC is probably enough to counter the effects of the EGR dribble.

 

[njaremka]

so.... i just looked up P0171 for the heck of it, since i thought it was one of the EGR codes. turns out, it may have nothing to do with the EGR.


This is what the service manual has to say:

DTC P0171 - Fuel trim system too lean
DETECTION CONDITION
PCM monitors short term fuel trim (SHRTFT) and long term fuel trim (LONGFT) values when DRIVE
MODE 1 is run. If fuel trim exceeds preprogrammed criteria, PCM determines that the fuel system is too
lean.

Diagnostic support note
This is a continuous monitor. (FUEL SYSTEM)
MIL illuminates if PCM detects the above malfunction conditions in two consecutive drive cycles.
PENDING CODE is available if PCM detects the above malfunction conditions during first drive cycle.
FREEZE FRAME DATA is available.
DTC is stored in PCM memory.

POSSIBLE CAUSE
Misfire
HO2S (front) deterioration
HO2S (front) heater malfunction
PRC solenoid valve malfunction
Pressure regulator malfunction
Fuel pump malfunction
Fuel filter clogged or restricted
Fuel leakage on fuel line from fuel delivery pipe and fuel pump
Fuel return hose clogged
Leakage from exhaust system
Purge solenoid valve malfunction
Purge solenoid hoses improper connection
Insufficient compression

it is entirely possible that the EGR valve could cause a lean condition by sticking open. if you were leaning towards replacing it anyway, i would do that and see if the car improves. if not, start checking stuff of this list.

 

[bwlknsn91]

so.... i just looked up P0171 for the heck of it, since i thought it was one of the EGR codes. turns out, it may have nothing to do with the EGR.


This is what the service manual has to say:


it is entirely possible that the EGR valve could cause a lean condition by sticking open. if you were leaning towards replacing it anyway, i would do that and see if the car improves. if not, start checking stuff of this list.

Awesome, thanks! Where did you find this info? And do you think it could possibly be the IAC valve?

 

[njaremka]

with the mileage these cars are racking up, this post should be on the front page...
http://www.mazdas247.com/forum/showthread.php?123744855-3rd-Gen-Workshop-Manual-(P5-MSP-MP3-also)

that's a link to the factory shop manual for the 3rd gen protege family. MIL codes are in the engine section.


i'm not convinced its NOT the EGR valve. the IAC valve is not in that list.