i'd go and just replace the egr for right now. that may be causing the other code to be thrown. the egr has a part to play in exhaust gasses at idle speeds, so i'm thinking thats why you got the 411 code. good luck
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89 GT AOD w/ shift kit, B&M rachet shifter, Trickflow intake, Crane (E-type) cam, 70Tb, 75MAF, 1.6 Rockers, Pulleys, MAC headers and H-pipe, Dynomax mufflers, K&N, 3 core radiator, white face gauges, custom interior, cobra R rims. 14.9 at 95.07mph with stock 2.73's.
89LX 2.3 Notch, daily beater!
MY89GT