03 Corolla Idle issue

[tigerclaws1318]

My 03 corolla would idle pretty low when coming to a redlight. Normally on a car it idles 600 to 800rpm depending on the car but my corolla seems to drop to about 500rpm and then back to like 700 800rpm in like 3 seconds. Even at 700rpm in gear the car still vibrates and shakes a lot. Probably motor mounts are going bad.
I thought my MAF sensor was bad or covered in oil considering I use to use K&N drop in filter. I brought a new sensor from the dealer for $170 and the idle issue is still there. Next thing I did was clean out the throttle body. Sprayed carb cleaner and cleaned it up for a while. A lot of carbon buildup in there. I thought that would solve the probably but nope. Idle would still drop really low.
The car has 70k miles on it now and has been well maintained. I do all the maintance work on the car myself. My next guess would maybe be a clogged EGR passage.

[jonjoe]

i feel your pain man im having the same problem 65k on the clock 05 i cleaned the throttle body too and put a new air filter for good measure still the same its only like that 2 months so I'm thinking it has to be a sensor or a air leak throttle body was not to dirty but i didn't spray into iac valve did you.i didn't want to damage it i used wynns injector and carb cleaner to clean the t/b if i find out what it is ill post it up here let me know if you find out yourself..good luck mate

[dorman68]

The intake manifold gaskets are a fairly common problem for the 2003-08 1zzfe corolla. I would replace the intake manifold gasket as you may have a slight vacuum leak causing your issues, it is a very cheap DIY repair.

[XR2003]

Originally Posted by dorman68

The intake manifold gaskets are a fairly common problem for the 2003-08 1zzfe corolla. I would replace the intake manifold gasket as you may have a slight vacuum leak causing your issues, it is a very cheap DIY repair.

agreed

also look into cleaning the IACV, if you cleaned the throttle body some of that residue gunk may have fallen unto the IACV.