Hey folks I just purchased a 97 Olds Bravada it has 4.3 l V-6 and 107000 miles the Service Engine Soon light is now on and when first started the idle shoots up to about 1800 then will slowly come down to about 1000if I turn the A/C on it comes down to about 7 or 800 once I shift to D it goes up to about 1000 again if I drive any distance when I let off the gas the RPM's stay at about 15 -1600 I do not need to apply gas if I want to coast at this speed. When I aply the brakes as coming up to a stop sign it stays around 1200untill I get stopped and then the idle drops to about 7 or 800 and the whole vehicl shakes and jumps. After a couple seconds all that will calm down and it stays steady and smooth at 750. I used a buddys code reader and it has 2 - error codes all they say is Idle speed high and Idle speed low. I have replaced MAP and TP sensors any ideas? Please help I dont have much hair left to pull out !!!
thanks in advance