I reset my ECU and followed the other procedures on technosquareinc.com with success. My idle went down to 600 rpm's from 900 rpm's and the CEL light went off. Today it's back on and the idle is at 900 RPM's. I don't think I broke anything because it kept the settings for a day or two. But why is the idle high again and CEL on again. Does anyone have any clues? Thanks in advance.

 

You might have F'd up your TB. What year do you have? The 5.5th gen TB are very finicky.

 

I have a 2002 SE. It doesn't make sense that the idle would go back to normal and the light would go off and then two days later it goes back to a high idle.

 

I have a 2002 SE and had the same EXACT problem after cleaning my throttle body. I got the code P0507 I believe and it was basically "high idle". I checked everything out and couldn't find the problem. I thought for sure it was the throttle body and bought one but it was the problem. I was fustrated and brought it to the dealer and found out it was the ECU that went bad.

See what code you are throwing. Did you disconnect the throttle body plug before cleaning? I wonder if that's what caused my ECU to die.

 

Hi,

I cleaned my TB with the car running and moved the butterfly by hand. THe car runs good and has power. It's onlu the idle that is high and the CEL is on. It stayed off for a day or two after resetting everything. So the dealership changed out your ECU? I wonder if there is a way to reflash it...

 

Well I had the same problem for over a year...learned to live with it.

I went down to Florida from New Jersey in my car and it magically fixed itself.

That's what they told me...but that was suck

 

Yeah, the dealership replaced the ECU under the Emmissions Warranty.