I was driving back from work and when i came to a stoplight, my car started to idle at 2100 rpms. It was fine the rest of the day. When i got home, i unplugged the battery and started it back up and it idled at 1400 rpm but gradually rose to 2100 rpm again. What could it be?

 

my advice is look around it could be a hose.

 

Tps

 

how can i test if the tps is bad? I already checked the throttle cable and its fine.

 

I had to buy a new tps. Because when I sat in my evo and had the mechanic tune it while I was inside. The revs. Where high low u name it..the tps. Housing was also cracked. But I gave it a try and me thinking. It was OK when it wasn't...bad idea....if I were u have someone tune your tps back and fourth until your at around 1100 that's where I keep mine after I naught a new tps. Drive for a while and when ur done driving always check to see of it came loose...I had to tie mines down with tie straps dude lol if everything's fine then probably your tps. Is bad...this is only my opinion on checking your tps BUT also keep in mind vaccuum leaks, maybe The egr valve (I dobght that though) check ur intake manifold ..or best of all autozone does a free computer check give that a try..lemme know how it goes