[RABarrett]

If someone could assist in the definition of the code, I can assist w/ troubleshooting. W/ respect to the noise, two things come to mind. The first, and most likely, is a plugged trans filter. The restriction may be causing the pump to cavitate, affecting directly the shift quality due to low pressures. This situation could also cause the 1811 code if it relates to a vague powertrain code. Vague codes include such things as random misfire. If the trans intermittently slips, vague codes such as random slippage may be set. The other possibility is the pump or pressure regulator valve may be intermittently affecting fluid pressures, causing the same problems. Ray