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"Reduced Engine Power" PLEASE HELP!!

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Old Nov 12, 2010 | 12:12 AM
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Default "Reduced Engine Power" PLEASE HELP!!

I have a 2006 Z06 and I am having issues with my car going into “reduced engine power” often and I have tried almost all that I can think of to fix it. When it does this, it reads a code about throttle voltage correlation (I think P2138 if I remember correctly but that may not be the exact number). The problem only occurs at low throttle position. If you turn the car off and back on it usually resets and fixes the problem or you can clear it with code scanner. After some suggestions, I replaced the APP sensor but no help. I have also checked continuity and resistance to ECM. When the problem started happening, I had a few aftermarket items: electric water pump, headers, exhaust, line lock, Pioneer radio and triple disk clutch. If anyone has had this problem, please post possible solutions. If you have not found a solution, please post anything strange or not stock (regardless of how insignificant it may seem) on your vehicle and any clues that you might have so we might be able to solve the problem. One clue that I have is that one day I got locked out of the car because the battery connections were not very good (they aren’t the best of quality). On the drive home, the “reduced engine power” problem occurred way more than usual (10+ times in 10 miles, I reset the code with scanner each time it happened and it restored power). I fixed the battery connections and the problem didn’t reoccur for a few drives later. This mean it may be voltage problem?? I installed high output alternator to try to fix problem, again no help. Please help in any way that you can.

Josh
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Old Nov 12, 2010 | 01:22 AM
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How old is your battery?
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Old Nov 12, 2010 | 01:31 AM
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Went that route too. Replaced it a month or two ago. Not the problem.
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Old Nov 12, 2010 | 01:41 AM
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Any work to the throttle body?
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Old Nov 12, 2010 | 01:53 AM
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Originally Posted by jatolbert
I have a 2006 Z06 and I am having issues with my car going into “reduced engine power” often and I have tried almost all that I can think of to fix it. When it does this, it reads a code about throttle voltage correlation (I think P2138 if I remember correctly but that may not be the exact number). The problem only occurs at low throttle position. If you turn the car off and back on it usually resets and fixes the problem or you can clear it with code scanner. After some suggestions, I replaced the APP sensor but no help. I have also checked continuity and resistance to ECM. When the problem started happening, I had a few aftermarket items: electric water pump, headers, exhaust, line lock, Pioneer radio and triple disk clutch. If anyone has had this problem, please post possible solutions. If you have not found a solution, please post anything strange or not stock (regardless of how insignificant it may seem) on your vehicle and any clues that you might have so we might be able to solve the problem. One clue that I have is that one day I got
locked out of the car because
the battery connections were not very good (they aren’t the best of quality). On the drive home, the “reduced engine power” problem occurred way more than usual (10+ times in 10 miles, I reset the code with scanner each time it happened and it restored power). I fixed the battery connections and the problem didn’t reoccur for a few drives later. This mean it may be voltage problem?? I installed high output alternator to try to fix problem, again no help. Please help in any way that you can.

Josh
From your profile: "Kooks 1 7/8 stepped C6R headers with 3 inch merge collectors, Dewitts HD aluminum radiator, Meziere electric water pump, Zip-Corvette bump steer kit, Custom line lock (button hidden in shifter boot), Corsa Sport Exhaust system, Halltech Race Filter, RPS triple disc carbon-carbon clutch."

I'd start by completely demodding it, except for maybe the clutch, and have a dealer flash a stock calibration into it.

If that didn't solve it, then I'd sell it with disclosure as to what was going on with it, and let the money made from the sale of the mods, go towards the loss I would inevitably take for selling what would be essentially, damaged goods


I hope post 31 is your answer and it is ironic that you ended up buying that same car.

http://forums.corvetteforum.com/c6-z...idiculous.html

Originally Posted by jatolbert
I ended up buying this car from the guy without him telling me it had this problem. He never got it fixed but it made it through the first few days of ownership without doing it. I replaced the pedal assembly, but no help. Still reading the same code. Any suggestions? A few days ago it stated doing the problem continuously but ended up just being bad battery connection. Fixed that, then right back to same old, same old of every now and then.
Damn. Would have been nice if you had known about this issue going in. The problem was first described on this board 7/22/09. And then again 1/09/10.

http://forums.corvetteforum.com/c6-z...r-problem.html

According to the 1/09/10 thread, you buy the car approx two weeks after 1/18/10,..... just 20 some days after the 1/09/10 thread, and don't even know about the 1/09/10 thread until some time in February of 2010, describing the trips to the dealership, etc.

The thread starter, hasn't been on here since June of 2010.

And now you have inherited this headache???

Oh well. That's why I stay away from buying modded cars.

At any rate, good luck with it and I hope you figure it out.

Last edited by '06 Quicksilver Z06; Nov 12, 2010 at 07:55 AM.
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Old Nov 12, 2010 | 03:09 AM
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It's a long shot given how moused that car is, but make sure that you have the correct size tires.
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Old Nov 12, 2010 | 10:15 AM
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The throttle body is completely stock. And yeah, I never had a foregut before so I was never on the forum before hand to see that he had this problem before hand.


Josh
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Old Nov 12, 2010 | 10:22 AM
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If you're getting code P2138 that is telling you that your Accelerator Pedal Position Sensor is bad OR......maybe you'll be lucky and just need to check the connector at the pedal and reseat it if it's loose. It's very common......you'll probably need a new Accelerator Pedal assembly. Here's a recent thread about it:

http://forums.corvetteforum.com/c6-t...-traction.html
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Old Nov 12, 2010 | 11:32 AM
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Originally Posted by '06 Quicksilver Z06
From your profile: "Kooks 1 7/8 stepped C6R headers with 3 inch merge collectors, Dewitts HD aluminum radiator, Meziere electric water pump, Zip-Corvette bump steer kit, Custom line lock (button hidden in shifter boot), Corsa Sport Exhaust system, Halltech Race Filter, RPS triple disc carbon-carbon clutch."

I'd start by completely demodding it, except for maybe the clutch, and have a dealer flash a stock calibration into it.

If that didn't solve it, then I'd sell it with disclosure as to what was going on with it, and let the money made from the sale of the mods, go towards the loss I would inevitably take for selling what would be essentially, damaged goods


I hope post 31 is your answer and it is ironic that you ended up buying that same car.

http://forums.corvetteforum.com/c6-z...idiculous.html



Damn. Would have been nice if you had known about this issue going in. The problem was first described on this board 7/22/09. And then again 1/09/10.

http://forums.corvetteforum.com/c6-z...r-problem.html

According to the 1/09/10 thread, you buy the car approx two weeks after 1/18/10,..... just 20 some days after the 1/09/10 thread, and don't even know about the 1/09/10 thread until some time in February of 2010, describing the trips to the dealership, etc.

The thread starter, hasn't been on here since June of 2010.

And now you have inherited this headache???

Oh well. That's why I stay away from buying modded cars.

At any rate, good luck with it and I hope you figure it out.
if it's not a stock Z06 it must suck. Wow you never stop
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Old Nov 12, 2010 | 12:31 PM
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Originally Posted by jatolbert
The throttle body is completely stock. And yeah, I never had a foregut before so I was never on the forum before hand to see that he had this problem before hand.


Josh
If you read through some of the other threads with this same problem you will find that some were corrected by fixing a sticky throttle body.
The car is drive by wire, there is no physical connection between the accelerator and the throttle body. If the throttle body butterfly gets hung up and and the position sensor in it is showing it is somewhere other than where it should be in relation to where the accelerator is being depressed, It may be giving you your code for the accelerator being out of correlation (in relationship to the throttle body)

You said you already replaced the accelerator sensor and that did nothing. And it appears to happen during a particular part throttle condition (or when the throttle body blade in in a particular position). This would appear to support this theory. It should not cost anything to pull it off and inspect it and possibly clean it or recenter the blade in the bore.
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Old Nov 12, 2010 | 12:47 PM
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Originally Posted by EDinPA
If you read through some of the other threads with this same problem you will find that some were corrected by fixing a sticky throttle body.
The car is drive by wire, there is no physical connection between the accelerator and the throttle body. If the throttle body butterfly gets hung up and and the position sensor in it is showing it is somewhere other than where it should be in relation to where the accelerator is being depressed, It may be giving you your code for the accelerator being out of correlation (in relationship to the throttle body)

You said you already replaced the accelerator sensor and that did nothing. And it appears to happen during a particular part throttle condition (or when the throttle body blade in in a particular position). This would appear to support this theory. It should not cost anything to pull it off and inspect it and possibly clean it or recenter the blade in the bore.
Did that a few months ago. Took it off and polished it. Moves freely but problem still exists.
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Old Nov 12, 2010 | 01:16 PM
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Originally Posted by jatolbert
Did that a few months ago. Took it off and polished it. Moves freely but problem still exists.
Any chance that the sensor in there could have been damaged or is out of calibration and giving a false position?
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Old Nov 12, 2010 | 03:07 PM
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What happened to our old Car????????????????????????

Whoever said removing parts and flashing, dont do any of that. Has anyone tuned the car that you know of even when Paul had it? Didnt you tell me you were changing the cam and heads on the car? Please tell me everything that was done after you guys put it back together, I will help you figure it out. You can PM if you like.
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Old Nov 12, 2010 | 03:08 PM
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Originally Posted by EDinPA
Any chance that the sensor in there could have been damaged or is out of calibration and giving a false position?
I guess but the previous owner has prev has replaced the tps.
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Old Nov 12, 2010 | 03:12 PM
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I can't believe someone said to go back stock. NOBODY on here realizes what car this is. This car was owned by Scott Hudson and built by Zip. It was hands down the fastest ZO6 with a stock engine at the time it was built. This car was a 10.60 car all day long and still had the stock motor in it. It is the most HP I have yet to see out of a LS7 with just some bolt ons. This car turned 517 rwhp, and tons of one off parts on it. You wanna sell it?
I am pretty sure looking at the mods on this car this is it. I am pretty sure this is the same car we are talking about now. Does it have a black strip with the MCM hood still?
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Old Nov 13, 2010 | 11:36 AM
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Originally Posted by '06 Quicksilver Z06
The thread starter, hasn't been on here since June of 2010.

And now you have inherited this headache???

Oh well. That's why I stay away from buying modded cars.


I'm sorry, but buying modded cars, you can't complain when the car turns into a nightmare. So many modded cars, so many problems. Engines that grenade, cars that run wrong, engine codes, etc.

I hope you find the problem but the guy who sold you the car should have given full disclosure about the problems it was having. If they didn't, I would sue them.
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Old Nov 13, 2010 | 12:32 PM
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Since you already bought a modded Z06 then it might be better for you to find out what the problem is and then fix it instead of ripping it apart and then buying another one.

If this is the car that ZIP mentioned then it really does sound impressive when it is working 100%. The problem with cars these days is that once you start changing electronics you better know what you are messing with. A good tuner might be able to "tune-out" the problem. I would never buy a modded car unless I know extreme details about the mods that were done to it and who did it.
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To "Reduced Engine Power" PLEASE HELP!!

Old Nov 13, 2010 | 03:10 PM
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Originally Posted by jabbott
I can't believe someone said to go back stock. NOBODY on here realizes what car this is. This car was owned by Scott Hudson and built by Zip. It was hands down the fastest ZO6 with a stock engine at the time it was built. This car was a 10.60 car all day long and still had the stock motor in it. It is the most HP I have yet to see out of a LS7 with just some bolt ons. This car turned 517 rwhp, and tons of one off parts on it. You wanna sell it?
jatolbert, if you are smart, you'll jump at this opportunity in bold. It might be the best offer, and the best chance you have of getting shed of this headache you bought that the prior owner sold you without full disclosure.

From their comment above, they are wiling to take it off your hands, knowing full well that it is jacked up. Saves you the trouble of trying to move it the hard way, and having to tell a potential buyer of this nightmarish tale.

That part in bold, they wouldn't have to ask me that $#** twice.

Going through this nightmare, and somebody knowing the problems I have been having with it, for months now, after, for whatever reasons, not knowing that it had this problem when I bought it, asks me; "Do I want to sell it?"

I'd tell them; "You're ******* right I want to sell it. Make me an offer."

Tell them to make you an offer. See how serious they are.

Anything even remotely resembling a serious offer, I'd take it and put this nightmare behind me.

A chance to put this whole nightmare behind you?????? I'd sell that emmeffer to them so fast it would make their heads spin.

Originally Posted by jatolbert
"Reduced Engine Power" PLEASE HELP!!
Originally Posted by jabbott
... This car turned 517 rwhp, and tons of one off parts on it. You wanna sell it?
They just offered you the best "help" you are going to get. They just gave you the answer to your prayers. Be smart. Take it.

Last edited by '06 Quicksilver Z06; Nov 13, 2010 at 03:41 PM.
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Old Nov 13, 2010 | 04:51 PM
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Originally Posted by RicK T
If you're getting code P2138 that is telling you that your Accelerator Pedal Position Sensor is bad OR......maybe you'll be lucky and just need to check the connector at the pedal and reseat it if it's loose. It's very common......you'll probably need a new Accelerator Pedal assembly. Here's a recent thread about it:

http://forums.corvetteforum.com/c6-t...-traction.html
i agree,,,, the pedal is jus ta potentiomater (variable switch like a dimmer switch i nyour house) if it looses a signal (pedal wigging out) then the computer will go into reduced power mode because it doenst want you to blow the enigine up if it happens to be stuck wide open. taking the connector loose and spraying with electrical cleaner, let dry and try it again. isnt fly by wire engine control great
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Old Nov 13, 2010 | 08:59 PM
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Originally Posted by jabbott
I can't believe someone said to go back stock. NOBODY on here realizes what car this is. This car was owned by Scott Hudson and built by Zip. It was hands down the fastest ZO6 with a stock engine at the time it was built. This car was a 10.60 car all day long and still had the stock motor in it. It is the most HP I have yet to see out of a LS7 with just some bolt ons. This car turned 517 rwhp, and tons of one off parts on it. You wanna sell it?
I am pretty sure looking at the mods on this car this is it. I am pretty sure this is the same car we are talking about now. Does it have a black strip with the MCM hood still?
This is that car. Original owner wanted to keep the hood so it now has black Z06 hood but halo is black along with strip on nose. The car runs amazing when it is running right. I ran a 2 gauge wire from alternator to post at fuse box and it really seems to help but it still has the problem every now and then. It seems to only do it now when it is hot. I'm thinking maybe this wire is getting hot (due to being near the header despite the fact that I put heat wrap on it) an causing the problem but I am unsure. Jabbott, I pm'd you earlier and I will do so again tomorrow. I have your email and spoke to you on the phone a few months ago. I might call you next week.

Josh
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