Seahag1978 Posted December 2, 2005 Share Posted December 2, 2005 The '86 is all pretty now. I took it to the custom exhaust shop to have the front half of the exhaust re-done. All went well. Sometime, while I wasn't looking, Massachusetts raised the cut-off for emissions exemption to 20 years... it actually passed!!!! Whew! The EGR light was on before the exhaust leaks were fixed. It's still on now. Sooo... can someone please explain the function of this little device and why it deserves its very own idiot light? It's a pretty smart car this Gen 2... told me my stop light was out this morning... gave it a little smack up the side of it and it was good to go. Link to comment Share on other sites More sharing options...
edrach Posted December 2, 2005 Share Posted December 2, 2005 Is the O2 sensor disconnected? Or did you add a weber? When I replaced the carb on mine with the weber, the O2 sensor doesn't change anything so after about 5 minutes of running the EGR light comes on. One of these days I'll put some black tape over it. The '86 is all pretty now. I took it to the custom exhaust shop to have the front half of the exhaust re-done. All went well. Sometime, while I wasn't looking, Massachusetts raised the cut-off for emissions exemption to 20 years... it actually passed!!!! Whew! The EGR light was on before the exhaust leaks were fixed. It's still on now. Sooo... can someone please explain the function of this little device and why it deserves its very own idiot light? It's a pretty smart car this Gen 2... told me my stop light was out this morning... gave it a little smack up the side of it and it was good to go. Link to comment Share on other sites More sharing options...
Seahag1978 Posted December 2, 2005 Author Share Posted December 2, 2005 Oh, is the EGR light for the O2 sensor? I don't think there's a weber on it. I have no idea what's in this one... haven't gone into the bowels of it yet... I'm not feeling too adventurous with the cold weather setting in The '78 doesn't have any of these gizmos on it. I need pictures... I think I better get a book. Link to comment Share on other sites More sharing options...
Subarian Posted December 2, 2005 Share Posted December 2, 2005 No, they're not related. The EGR light is a mileage-driven reminder to check the EGR. It doesn't in any way display an actual fault. You reset it by switching connectors under the left side of the dash, but I can't remember if they're green or blue. The EGR (exhaust gas recirculation valve) introduces exhaust gas into the combustion chamber to lower combustion temperatures. Its purpose is to reduce NOx emissions. You don't really need it on a Subaru. Many of us run with them blocked off. Link to comment Share on other sites More sharing options...
TomRhere Posted December 2, 2005 Share Posted December 2, 2005 The EGR light is on in my '86 BRAT, also. Going to dive into the dash wiring this weekend to see if I can figure out which connectors it is that needs swapped around. As stated, it's just a service reminder, comes on every XX,000 miles. Link to comment Share on other sites More sharing options...
Seahag1978 Posted December 2, 2005 Author Share Posted December 2, 2005 Jerry (bratsrus1) just PM'd me about some parts I'm getting from him. He said it's a wire all by itself to the left of the steering column that's either green or pink. I paid attention in kinnygarden and I learned my colors, so I can maybe fix this one? I'll have plenty more questions about this Brat I'm sure! Thanks! Link to comment Share on other sites More sharing options...
edrach Posted December 2, 2005 Share Posted December 2, 2005 No, they're not related. The EGR light is a mileage-driven reminder to check the EGR. It doesn't in any way display an actual fault. You reset it by switching connectors under the left side of the dash, but I can't remember if they're green or blue. The EGR (exhaust gas recirculation valve) introduces exhaust gas into the combustion chamber to lower combustion temperatures. Its purpose is to reduce NOx emissions. You don't really need it on a Subaru. Many of us run with them blocked off. Interesting; on my weberized '84 Brat, the EGR light comes on after about 5 minutes of driving and then stays on. But it always is off whenever I start the car for the first time. Link to comment Share on other sites More sharing options...
northguy Posted December 2, 2005 Share Posted December 2, 2005 It just does it for shock value, Ed. It's onwe of those drama queen instruments. Interesting; on my weberized '84 Brat, the EGR light comes on after about 5 minutes of driving and then stays on. But it always is off whenever I start the car for the first time. Link to comment Share on other sites More sharing options...
edrach Posted December 4, 2005 Share Posted December 4, 2005 Correction to my previous posts; it's the ECS light that comes on after about 6 min. of running. I think it's related to the EGR. Link to comment Share on other sites More sharing options...
idosubaru Posted December 4, 2005 Share Posted December 4, 2005 EGR: can the valve fail or cause any issues with drivability? does it affect gas mileage? better with or without? i'll be putting my EA82 together shortly and am wondering what to do with this. Link to comment Share on other sites More sharing options...
Seahag1978 Posted December 4, 2005 Author Share Posted December 4, 2005 Could the lack of operability of the ERG affect the emissions test... by letting more air in? I understand that it recirculates unburnt gasses? Just trying to get a handle on its function. Link to comment Share on other sites More sharing options...
NorthWet Posted December 4, 2005 Share Posted December 4, 2005 The EGR system's function is to allow a certain amount of exhaust gasses to be inducted into the engine to reduce PEAK combustion temperatures, thus reducing the production of oxides of nitrogen (a product of thermally-efficient combustion). The exhaust gasses act as both a charge dilutant and an energy sponge (absorbs the combustion heat, much as water injection does). Generally, EGR only occurs during part-throttle operation, so should not effect idle quality nor full-throttle power. EGR is NOT needed for proper operation of the engine. With a feedback fuel system (carb or FI with O2 sensor) the engine will receive proper A/F mixture. An EGR valve that is stuck open (they are subject to carbon buildup) can cause gross problems with idle and off-idle running. EGR will effect emissions levels if they test for NOx, or if it is stuck open and causing idle issues. It can effect mileage and drivability; both were MAJOR issues when first introduced, with some cars using 20% EGR at part-throttle. As a side note, I have been toying with the idea of using the EGR valve to enhance part-throttle specific fuel consumption... it might be possible to use it to increase the effective compression ratio and thus the average combustion temperature, yielding better average thermal efficiency. Have to deal with the charge dilution (tougher ignition conditions and slower flame propogation), plus probably needs to be hotter when inducted to reduce heat absorbtion. Link to comment Share on other sites More sharing options...
ballitch Posted December 4, 2005 Share Posted December 4, 2005 the EGR valve is a mileage driven instrument, every 60,000 miles it ocmes on, ten you reset it, odnt know how, i took mine to a mechanic. as far as it being on all the time, got no advice for you there. Link to comment Share on other sites More sharing options...
NorthWet Posted December 4, 2005 Share Posted December 4, 2005 the EGR valve is a mileage driven instrument... I assume that you really meant the "EGR light"... Link to comment Share on other sites More sharing options...
idosubaru Posted December 4, 2005 Share Posted December 4, 2005 an EA82 with EGR system will get better or worse mileage than one without? Link to comment Share on other sites More sharing options...
Seahag1978 Posted December 4, 2005 Author Share Posted December 4, 2005 the EGR valve is a mileage driven instrument, every 60,000 miles it ocmes on, ten you reset it, odnt know how, i took mine to a mechanic. as far as it being on all the time, got no advice for you there. Ahhh... the Brat only has 66,000 miles on it, so that explains it. It's snowing like heck here right now so when it slows up, I'll see if I can put my color skills to practical use. Link to comment Share on other sites More sharing options...
NorthWet Posted December 4, 2005 Share Posted December 4, 2005 an EA82 with EGR system will get better or worse mileage than one without? (semi-hijack) It will probably get negliglible-to-worse mileage. The EGR system is optimized for pollution control, not efficiency. (end semi-hijack) Link to comment Share on other sites More sharing options...
Seahag1978 Posted December 4, 2005 Author Share Posted December 4, 2005 (semi-hijack) It will probably get negliglible-to-worse mileage. The EGR system is optimized for pollution control, not efficiency. (end semi-hijack) As much information as possible is welcome. I had searched EGR and came up empty. Link to comment Share on other sites More sharing options...
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