Ok, I'm sure it's something small.. but I can't figure it out. My car runs like crap from idle to about 2000 rpm... then it runs great.

When sitting at idle the car is shaky, idle stays constant at 1000 rpm when sitting still, when in gear the car seems to stumble like something’s holding it back ( once in a while I’ll hear a pop in the exhaust ). Then at 2000 rpm, it’s like somebody pushes it from behind and it gets going … runs fine. When slowing down, out of gear, the car idles at 1000rpm to 1500 rpm ( you can see it jumping up and down ). Then once at idle, it’s back to 1000 rpm.
It’s thrown three codes, lean bank 1, lean bank 2, and idle system malfunction idle too high.
I think those are like 171 174 and like 570? I can’t remember them off the top of my head and I cleared them… the only thing that returned was the “idle system malfunction”, the lean 1 and lean 2 have not yet returned.
Ideas?

 

Make sure your throttle body and MAF are clean.

 

How can you expect advice when you don't even post what you're working on? Type of motor, type of car, mods, tuned/untuned etc.

 

What do I use to clean them?

 

It's in my sig.
Only mod is the 243 heads.

 

clean the MAF, worked for me.

 

sounds like it's running lean just as the codes state. Whenever I've messed around tuning a car and i lean it out it stumbles at idle and has no power under load until the fuel kicks in. Vacuum issue if your carburated?

 

The car's actually totally stock... only thing I've changed is the heads. I thought it might be a vacuum leak but I can't find a leak anywhere. I just ran the code reader again and I noticed that along with the idle speed code it also had the "C" and the "EV" on the reader blinking. I'm not sure what C stands for as I don't have the manual on me, but the EV is evap sensor.
Can those things go bad? If so how do I replace it? Could that be my problem?
The lean code has not kicked back on yet.. but I'll run the reader again when I get home. So far all it says is fast idle.

 

check the ICM it might be stuck open.

 

It's a vacuum leak.Easy checks is to pull the PCV,plug the intake and take for a ride.If idle is back to normal there is a leak in those lines. 2nd would be to pull the EVAP line off the intake and plug that -test with a drive.

 

sorry Iron fist I was looking at the first car in your sig and thinking you did an lsx implant.. lol

Like slowhawk said it sounds like a vacuum issue.. Do like he suggested or if you have a buddy with a smoke machine..they work SWEET for finding leaks

 

Ok thanks for the help guy.. I'll try all this stuff and post back in the morning. Dont' have a smoke machine though, but if it's a vacuum leak I'll just like the stealership fix the thing.

 

Any luck?? Sounds exactly how my car is idling!?

 

Ok, so I went and got a new evap sending unit, replaced the old one. That did nothing.
I unplugged the evap from the manifold, plugged the hole, drove around.. no improvement.
I then did the same with the egr, no improvement there.
Tried to search for a vacuum leak, no luck there...

I think I'm just going to take it in, as I can't find the problem.

 

Whip out your fuel pressure gauge and report your rail pressure w/ the engine at idle.