Engine strange idle

strange idle

so i've had this problem a while ago and now its back. i suspect it somehow ties into my poor gas mileage.

shortly after I start my car (in the morning or after the motor is cold), and i go driving and i stop at a red light (not long after engine reaches normal temperature), the car starts shaking and the RPM's jump between 450-600 rpm's, until i press on the gas. usually only happens once.

what could this be? a small vacuum leak somewhere? dirty injectors?

here's a rundown of what i've done in the past 10k

Oil change, Mobil 1 Syn. 5w30 (changed 500 miles ago, changed every 3k)
Filter Recharge K&N (2k miles)
New PCV Valve (3k miles)
New Spark Plugs (Denso Iridium IK16, 4k miles)
New 1st O2 Sensor (~600 miles)
Cleaned MAF (~800 miles)
TRD Exhaust (5k miles)
Seafoam (3k miles)
Fuel Injector Cleaner (500 miles, done four times in the last 6k)

any ideas/thoughts would be appreciated.

Somewhere in the last 10k my gas mileage started going to hell (20mpg city, 28 highway) and that strange idling happened.

THANKS!

sumthin similar to that is happenin 2 my car, gas mileage went to hell, here and there it idles kinda nasty.....

I suspect it could be the seafoam or the maf sensor

but I could be wrong

Mine did that once. I cleaned the MAF with zero residue electronic parts cleaner and reset the ECU.

i think ill try cleanin my maf

sddynamix:

If I remember correctly, you were having problems with your tread wear (edges wearing faster than center). I was having a similar problem. I had Toyota do a full check of all my suspension, ball joints, tie-rods, anything related to tire wear. Conclusion: alignment. California roads suck, I'm going to buy a lifetime alignment from Firestone for about $170. I'd recommend the same.

Firestone

sounds like your idler....just check....it.....