A question for those that blocked off there egr

[magnumP5]

Man, I don't get it. People are out there idling at 16:1 AFRs and don't throw CELs but my car will hiccup at idle once and will through the P0171. It's annoying...

Anyway, for sure open EGR is causing the lean issue. We currently have one member who has left the EGR plugged in but the pipe is not hooked up (he has a different IM) and so far he has not thrown a CEL.

 

[cougar10agREDUX]

your EGR should NOT be open at idle, just light load.

i have my egr unplugged. i think i'm gonna get a filter to see if it gets rid of the insufficient flow code

 

[808MP5]

hmmm... so if the EGR is unplugged it is left closed
i have no EGR bung on my manifold and i twisted my home depot egr tube in two seperate spots but i don't think its blocking it off completely... once i threw a cel for "EGR insufficient flow" erased it and it never came back

 

[cougar10agREDUX]

yes if it's not clogged it should be closed. i have a vaccum cap on the egr tube and it's not collapsing when the engine is running. if i push on it it'll collapse a little so my egr prolly needs to be cleaned.

ironically unpluggin the EGR does not throw a MIL. the DTC is from insuffecient flow which is the EGR boost sensor not seeing a big enough pressure difference in the manifold from when the EGR should be open, and when it should be closed.

if you're not getting the MIL anymore you most likely have a leak in the piping.

 

[808MP5]

if you're not getting the MIL anymore you most likely have a leak in the piping.

when you say leak in the piping you mean me not having it hooked up? so if i completly seal it i should get the insufficent egr flow MIL then yup... cuz i think that's what im shooting for... a completly sealed off EGR

 

[Speed3.5]

yeah, i'm in the same boat as you 808, i guess you can't escape the CEL but i bet it will not hurt performance other wise , it is emission related after all.

 

[magnumP5]

It also helps supress detonation...

 

[43975]

It also helps supress detonation...

what does? blocking it or keeping it?

 

[magnumP5]

what does? blocking it or keeping it?

Keeping it. Recirculating exhaust gas back into the combustion chamber lowers combustion temperatures thus reducing the potential for engine knock or detonation. It's also a convenient way to burn off any fuel that did not combust the first time. Yes, it technically reduces power as power is derived from the combustion that takes place. More combustion and higher temperatures mean more power but they also increase the chances of detonation occurring.

 

[Maxx Mazda]

But on the stock ECU it (within reason) can pull timing so knock doesnt occur, and on a standalone you definitly don't want the EGR, and can tune it well enough to keep from pinging.

 

[magnumP5]

With the stock ECU it still doesn't solve the case of allowing in unmetered air (in the breather filter case). Blocking it off altogether won't really cause any issues aside from throwing a CEL. With a standalone though, it really doesn't matter. Personally, I like to keep my car as driveable as it was stock so a full standalone isn't necessarily the best route.

 

[MSP2024]

my car does not throw a cel,is not running to lean or any of that s***,mine runs like a champ with the filter on it

 

[TiPapoute]

Geez, this makes me want to clamp the EGR out of the equation...

 

[magnumP5]

my car does not throw a cel,is not running to lean or any of that s***,mine runs like a champ with the filter on it

You have a wideband? If not, I wouldn't trust that narrowband autometer air/fuel gauge at all. IIRC, it only has three readings, rich, stoich and lean. It's rich if below 14.7:1, stoich at 14.7:1 and lean above 14.7:1.

 

[cougar10agREDUX]

so i finally put the filter on my EGR and plugged it back in. AFR's went apeshit when the egr opened. after about 10 miles it fixed itself tho. drove 250 miles so far, no EGR cel. No problems. still getting a code for my cat since i got some crazy rich spots i gotta fix. should just throw the non-fouler back on.

BTW i used a 12mm APC breather filter. lol don't hate.