90 TBird check engine light egr valve question

My engine light comes on and the code (31 if I remember correctly) tells me the egr valve is out of range(low).

So I spend $50 and replace the Egr valve and disconnect the battery to reset the codes and the same code comes on.

Is there an EGR sensor and where is it located? Thanks Anything else it might be? Emissions is coming up in September so I should get this taken care of. Thanks Gears

IIRC, your 90 has an EVP (EGR valve Position) sensor on top of the EGR valve. It tells the engine computer how far the valve is open. For $50, the new valve didn't come with one. That is likely your problem, it's a pretty high failure item. Code 31 means that the feedback voltage to the ECM from the EVP sensor is lower than it expects to see when the valve is open.(More EGR opening, more feedback voltage. There is also a vacuum solenoid that controls vacuum to the EGR valve. It's at the other end of the vacuum line to the valve. If it has failed, there will be no EGR operation, and low feedback voltage. They don't often fail, but they can. If you have a test light, check for voltage to the EGR (EGR Valve Regulator, or EVR) solenoid with the engine running. Then put the light on the other terminal. This will usually cause the EVR to apply some vacuum to the EGR valve. At idle, the engine will start to miss and shake slightly. This tells you the EVR is probably ok.

Hope this helps, Tom

A common problem of that year is:....The sensor is very close to in range/out of range. If the valve is working, take the sensor off of the valve (3 screws) and grind about an 1/8 inch off of the end of the sensor stem. ( the round, thin metal piece sticking out of the bottom of the sensor). Re-install and do the self tests again.