What's the worse that can happen if i don't adjust my tps?

Motor is a b20b if that matters.

 

You'll run rich/lean acording to how its off, bad gas mileage, may not idle/run well. Its somewhat easy to adjust though, just do it. Search "tps" and you'll find a diy from not too long ago on how to adjust it.

 

would a badly set tps cause a wonky idle? My idle sometimes sits randomly at 1900, then other times it'll idle at 1100, or even 900

 

For sure it would

 

yeah, my buddy car is idling at 1500 and back down.

 

well today i was getting a CEL for TPS, (my boy broke it off when we did the swap ) when I start the car the motor idles at 2K, so I changed the TPS and no more CEL, but I didn't get to start the car up since its midnight here in NY (very loud @ open header , my pops will kick my ***