I cleaned the throttle body and MAF sensor trying to solve the rough idle when stopping at a red light. The car idles at 700 to 750 when I put the shift in P which is normal. However, if I shift in D without my foot on gas paddle the engine goes up to 1500 rpm and the car speed is 10 to 15 mph. I guess both the RPM and MPH are a little bit high. So where is the problem? I did not disconnect the battery when did the cleaning. Is this culprit? Thanks!

 

Take a rag, put some throttlebody cleaner on it and open up the butterfly valve. Run the wet part of the rag over the edges of the butterfly valve (the thin part). Then using some of the throttlebody cleaner, also spray at the point where the shaft for the butterfly valve enters the air stream. Any gum where the shaft rotates or on the edge of the butterfly valve can cause this.

Once you have done the above, reset the computer and see what you have then. Obviously you moved something to change the "problem". So, you are on the right track.

 

Did you use the recommended maf cleaner for the maf, or did you clean it with the throttlebody cleaner?

 

CRC MAF cleaner for MAF and CRC TB cleaner for TB.

I just took out two engine control fuses and one automatic transmission fuse from engine compartment fuse box and waited 10 mins and plug them back in, and now the problem gets better. No more 1500 rpm in D. I will test the car more this afternoon.