Toyota Repair: egr valve and code 71, 1991 toyota camry, toyota camry

Question
Hi Tim,
    I have a 1991 toyota camry 4 cylinder 168,000 which has a check engine light code 71.  I want to remove the egr valve to clean it however the throttle body blocks my getting an open wrench to loosen the pipe fitting underneath it.  Do I need to remove the throttle body first to get to the egr valve? Also after I clean the egr valve and reset the ecu and if the light remains on what do I do next.  I tried Seafoam at the brake booster and cleaned the intake valve with no success.  Also last year I replaced the egr modulator.  Can you help please?  Thanks in advance.

Answer
Stan,

Before you remove the EGR valve I would test it on the car.  You will need a hand held vacuum pump to test it. With the engine running apply a vacuum directly to the EGR valve port. It should open and the engine will start to cough and run roughly. If it does your EGR valve is working properly. Also, check that it does not loose vacuum.

Next, check your vacuum lines from the throttle body to the modulator. They should have a vacuum applied only with the throttle plates open above idle. These ports are common to clog up so check them carefully. Use compressed air to clean them out and clean inside the throttle body as well.

Last check the exhaust tube coming into the bottom of the modulator for carbon build up. There should be a vacuum aplied on the modulator output above idle.

Good Luck!!