I’ll try to keep this short…
Having idle issues. Started after the Radix install, but I don’t think they are related. Hooked up to scanner today and got code: P0507, Idle Control System High RPM. Was told to check O2 sensor readings:
02S11 was bouncing all over the place, from what I was told, this is what it is supposed to do. Anywhere from 0.900 to 0.050 or so.
O2S12 was moving from .135 to .070
O2S21 was .035 to .050 and
O2S22 was the same at 0.035 to 0.050.
So, one O2 sensor is all over the place and the other 3 are staying pretty close together. According to the guy I spoke with O2S11 is right and the others are not. How can 3 O2 sensors go bad at once? Or are these ranges acceptable?
My idle is crap, it moves all over the place. At start up it shoots up to 2K and then comes down to 1200, then creeps down to 800. Put it in gear and it jumps a little to 1000, let off the brake and let it roll for 2 or 3 seconds and it jumps to 1200 and I’m going 20mph in second gear without touching the gas pedal once. Start down the road and it drives great, accelerates fine, no issues, just at idle. After I erased the code, it came right back so something is junked up somewhere. The guy who wrote my tune says he can’t find anything in the tune that’s not right and spent 20 minutes on the phone trying to help me trouble shoot. Any suggestions? Which O2 should I replace? I checked the fuses for the sensors, they are good.

 

Is baumgardner your name? I new someone with that name around Jax.


With your O2's, i dont think there bad. I would recheck your vacume lines and IAC. It sounds like its pulling extra air in from somewhere, not a bad O2.

 

Yep, Chris Baumgarder. I live in the panhandle near Pensacola. Don't have any relatives in Jax, but you'd be suprised how common my name is. There is actually another guy in my town named Chris Baumgardner.

About the problem. I don't know what an IAC is so you'll have to help me out on that. I've listened to it under the hood while it running, but in park it actually runs ok. No vacume leaks I can hear. It's while in gear it goes ape sh*t. I don't understand what the SES code means, talking about the high rpm.

 

Did it do this before the tune or is it since the tune? There are different idle tables and timing tables for Park and in gear. It may be in the tune.

IAC is idle air control, and is the small solenoid looking thing on the side of the throttle body.

Are you in the Navy?

 

It didn't start this until the new tune for the Radix. I have talked to the tuner a couple of times and even had a new tune done and instaled and it didn't solve it. I am trying to trouble shoot other things to make sure it is the tune. The SES code is for the Idle control system so maybe the wiring is pinched or loose somewhere. The tuner said he went through the tune with a "fine tooth comb" and can't see where it would have any problems. He's done other tunes for me b4 the radix and never had an issue. I guess I will look at the IAC and see if one of the pins has come loose or something.
I am in the Air Force, stationed at Hurlburt Field which is in Fort Walton Beach. You military?

 

I'm pretty sure the Problem is solved. This set up was originally on a 4.8 with a TB by wire system. I have an electronic TB. On top of the Radix, are the threaded ports for the screws, which hold the bracket for the throttle cables. I have no cables, so I need no bracket. However, the holes were not plugged. One is sealed any way because it doesn’t go all the way through. The other goes straight into the intake after the TB. That hole was sucking air like a fighter pilot at 35 thousand feet. I covered it with tape and the idle smoothed right out. Gonna take a spin and see hoe she does. Could this have caused performance issues under boost or not really? Damn, I feel dumb. But hey, I didn't install it a trained mechanic did.

 

Figured it was a vacume leak. LOL

It wouldnt affect boost any, just your idle. But glad to hear you found it.

 

I was going to say that it sounded like a leak too. I removed the same bracket on mine but put the screws back in to plug off the holes. I had to buy a plug so I could remove the EGR pipe too.