OK well I have searched here and found similar situations but no definite answer yet as mine is a little different.

When I first start the car after the car hasn't been started in a few hours or over night the car starts right up and idles at about 900 rpm's in park, but if I put it in neutral then idle goes to like 1600 rpms. If I put the car into gear and hold down the brakes then the idle will go back down to 900 rpms, but if I let go the it goes up to 1400 rpms. Also after the car warms up if I put it into park then it will go up to 1400 rpms and then drop down to 1100 rpms.

The SES light has come on to say that I have a "High Idle" and said that one of the solutions was to replace the IAC Sensor (Idle Air Control), so I did that and still have the same thing. All of the vaccum lines seem to be good and I've cleaned out the throttle body and the MAF sensor and still nothing. I don't think my Traction control/cruise control box is messed up, meaning holding the blade open, since it idles fine when I'm in drive and have the brakes on.

I can cruise down the road going 45 mphs without having to hold the pedal, now that seems wrong...

Anyone got anything...

As for the loss of power, unless I got used to 450 rwhp really fast it seems that the car has lost a little power. Even my dad has said that it isn't the same from when I first rolled it off the trailer after getting back from the tuner. I did recently blow one of my cats and a large chunk came out my driver side tailpipe. So I had the cats removed and installed cutouts and the chunk that came out of the tail pipe seems about the right size that came out of the cat itself so I don't think there is anything left in the exhaust.

Anyone got anything here.

Mods in Sig

Any help is greatly appreciated!

 

I would say a bad throttle position sensor; thats what fixed mine when i had similar issues. My SES light came on and started blinking, for a misfire; the code scanner showed it was the TPS...

 

Ok, well I changed my fuel filter and VIOLA idle issue fixed! They say that if you switch to E85 to change your fuel filter and i had one laying around so I changed it real quickly. I guess I had gunked mine up from switching fuels.

But I have another problem I went to go wide open throttle and when I got to about 5500 rpms it stuttered REALLY BADLY... Now could this be because I got it tuned with a gunked up fuel filter and now since it has a new one that I'm getting to much fuel...

 

Well it is doing the "High Idle" again... I fixed the fuel filter when the cut outs where off and when I put them back on it did the high idle again...

Also now the car is studdering althrought the power band... I looked at the plugs and they don't appear to be fouled out, do you think it could be my wires or even my coils... anyway to test this before I go buy a new set of MSD wires...

When I rev the engine it seems fine it is just when I'm going WOT

 

How does it act with the cutouts open?

 

Well it acted great when I had the cutouts open and then changed the fuel filter, but when I put the cutouts on it idled high. So I decided to take the cut outs off and it was still idling high.

So my dad had bought a gallon of seafoam a couple weeks back and I saw it today during lunch and decided what the hell... So I put 8 oz in the gas tank because I had half a tank and then I put 8 oz in the brake booster vaccum hose that leads to the back intake manifold with the car on and let the las little bit kill the engine and let it sit in there.

10 mintues later I checked to make sure everything was plug up and shut the hood. Got in the car and started her up, it stubled a bit becuase of having the seafoam in the intake but idled great. I looked in my rear view mirror and DAMN was there a lot of blue smoke coming out of the exhaust, gues it needed a little cleaning! So for some fun I backed out of the driveway and gunned it down the road and let a huge cloud of smoke for about a quarter of a mile. It was cool it looked like I did a massive burnout.

It doesn't feel like ALL of my power is back yet though, but lets hope this is what it needed and nothing else pops up

 

I give up I don't know what is going on...

Not the car is spurting around 40mph and it is sputering from 4500rpms on up. The SES light was on for the past couple of days so I went to go see what it said and get it cleared.

High Idle
Bank 1 Lean
Bank 2 Lean
O2 Bank 1 Malfunction (could this be because my cut outs are open...)

I just wish I had the money to spend on a scanner or a tuning problem just so I can see what is going on!

 

I'd set the exhaust up for how I was going to run it then take it back to the tune shop and get it tweaked.