I cleaned my fuel system about two weeks ago. I cleaned behind and in front of the flap in the throttle body, and I ran fuel system cleaner through the engine through a vacuum source on the throttle body(the one that connects to the fuel pressure regulator). Ever since then the car will rev to about 1800 rpms back down to 800 rpms about three a four times over when I'm coming to a stop coasting in nuetral. I put the hose back on. what could be the cause?

 

another vaccum leat or idle position sensor

 

You are running rich this will cause a shity idle.Did the code set after this.Or are we talking 2 different cars.

 

clean your iacv, use seafoam or caeb cleaner, make sure the screen inside is clean

 

i would double check ur vaccum lines first and make sure everythying is good shape, aka, no cracked hoses etc. it thats not it, then move to the idle air control valve. is the car throwing a cel?
if the IACV was bad, it should throw a code, same with the TPS.

 

probably IACV.

 

Same code. The code came way before.

 

I would take every ones advice i would say the same.How is the code coming along.

 

Thanks for your concern. I haven't gotten around to it. I need fuel pressure guage kit.

 

I changed the vacuum hose between the fuel pressure regulator and the throttle body. There was a very small hose at the very end of the hose where the hose connects to the TB. So far it has helped the problem, but the car still does the same thing but not nearly as often. I think I already cleaned the IACV though. Is that the flap inside the throttle body?