I just got a CEL code 7, which is the TPS sensor.
I did adjust the idle screw last week to rise the idle RPM to around 900 rpm, because the engine would bounce up and down and stall occasionally when the engine get hot in traffic. That stalling problem went away but the idle still bounce up and down after I adjust the idle screw.

So my question is that if it is possible that I adjusted the idle screw too much, so it give a CEL code for the TPS sensor? Or it is the TPS is going bad, that's why I get the CEL and have the bouncing idle and stalling problem?

 

Im pretty sure your TPS has gone bad. Check the voltage on it before you go replacing. Those sensors suck ***. That could definatly be the reason for your fluctuating idle too.

 

what you can also do is take of the throttle body and adjust the TPS by first loosen the 2 screws that hold the TPS, put the tb back on and start the car and mess w/ the TPS by moving it back and forth until your idle is settle to a steady rpm. If the 2 screws cant be loosen w/ a screwdriver use a disc grinder and grind a straight line in it to use a flat-head screwdriver to take it off. If adjusting the TPS doesnt work then use a voltmeter to check for continuity which is at close throttle voltage should be 0.5 and at WOT should be 5.0 if that doesnt work then the TPS is bad. another thing you can check is your coolant. when your motor dont have enough coolant or their is air in the system, your motor will idle up and down becuz there is a sensor on the back of the intake manifold that controls your idle and it need consistent coolant or water but if air is in the line then the idle will bounce. before checking everything else do the coolant method first. absolutely no air in the line.

 

Thanks for the tips, I will try that first.
I really don't want to change the TPS sensor if I don't have to.

 

you dont have to but if you have modify something on your motor or the carbon build-up in your tb can cuz the butterfly to seat at an angle rather at it origin / straight so there the TPS needs a bit adjusting to those voltage number I provided earlier to allow the idle to be steady again. but make sure u check your coolant first.

 

checked the coolant, it is at the normal level.
Should I buy some TB cleaner to clean it up now and see?