The 1991 Geo Metro EGR valve can be located on the air cleaner housing. The valve will be on the back of the housing.
I HAVE NOTICED THAT FROM 87-92 MANY AUTO MAKERS DID NOT USE AN EGR VALVE...EXAMPLE 88FORD TAURUS,92 TOYOTA COROLLA
do you mean the EGR valve? it's at the base of the intake manifold
changing the thermostat in a 1991 geo metro 1.3 liter
geo metro had a problem with the egr valve going bad causing the # 3 exhaust valve to burn, which could cause a lack of power in the engine performance. if this exhaust valve was burnt due to a faulty egr valve the new egr valve could have gotten clogged again causing a check engine light to reappear.
Looking at the front of the engine, it is on the right hand side of the engine, just below the o2 sensor. It will have two tubes going into it.
Remove the EGR valve vacuum lines. Remove the EGR valve retaining screws. Wash the EGR valve in hot water. Allow the valve to thoroughly dry before installing it.
no adjustment possible
After replacing the EGR valve, use the diagnostic tool and erase codes then read the codes again. I had the same problem on my 97 geo metro. After replacing the egr valve, the check engine light stayed on. After a while it was suppose to clear itself but it didn't. So I went to autozone borrowed their diagnostic tool, erased the codes and then my car passed and the check engine light went off.
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After unbolting the EGR valve, clean it with a carburetor spray. Allow it to dry completely before reinstalling the valve.
If its from 85 then its NOT a geo metro engine. It is probably a Chevrolet Sprint engine because they only started making Geos in 88. If you need an engine for your 95 Geo then you could use one of the following: 1991 - 1995 Geo Metro engine. 1991 - 1995 Suzuki Swift Engine, and 1991 - 1995 Pontiac FireFly engine. Hope this helps :)
egr valve