Chk Eng light after hard acceleration

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Jan 21, 2006 | 01:19 AM

SueEmAll

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Joined: Dec 2005

Posts: 34

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From: Louisville area

Chk Eng light after hard acceleration

I have recently installed a Diablo tuner, MBRP 4" exhaust and the quik filter mod. Now, when I get into the throttle real agressively and near redline, the check engine light comes on and stays on for a minute or 2 before going off. What is this and should I be checking anything?

Jan 21, 2006 | 02:09 AM

cookie88

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Joined: May 2001

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From: Cabot, Arkansas

What does your boost gauge read when it spooled up like that?

Jan 21, 2006 | 09:24 AM

4X4 IN REFUGIO

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Joined: May 2005

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From: Refugio, Texas

Pull And Read The Codes With Your Tuner And Then You Can Clear Them.

Post The Codes On This Forum And We Can Help You With Them. More Than Likley Your Codes Will Be Normal Codes That You Get When Using A Tuner Or A Chip.

Jan 21, 2006 | 11:40 AM

DieselFuelOnly

Mountain Pass

Joined: Nov 2005

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its probably an overboost code. Above 25 psi or so of boost, the light will come on and defuel the engine. Happens whenever I really romp on it too.

I hope you have gauges to go along with those mods of yours.

Jan 21, 2006 | 11:52 AM

PowerstrokeJunkie

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Joined: Jul 2005

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From: 21791

once the manifold absolute pressure (MAP) sensor reads 22-23 psi of boost, it throws a code and puts on the SES light. 22 pounds is NOT normal for a stock engine, and the PCM still thinks it is running the stock program instead of a tune. what you need is something you place between the sensor and the intake manifold pickup. there are two options for doing this- a regulator and a boost relief valve (not to be confused with a blow-off valve). i personally have a boost relief valve, but i threw the SES light last night with moderate throttle on 140hp setting. i am going to be going with a regulator soon. the difference between the two is that the regulator restricts the opening and only lets a certain amount of pressure through. it is also adjustable. the relief valve has springs in the device that let out pressure above 22 psi. obviously this causes a "boost leak" albeit a small one. some believe that the relief valve is not a good option, because all the boost produced should go to the engine, and i believe that. that is why im going with a regulator.

regulator-

http://www.itpdiesel.com/store.php?c...on=show_detail

boost relief valve-

http://www.blackclouddiesel.com/Ford/ourfordstuff.htm

Jan 21, 2006 | 11:56 AM

Fire Rooster

Posting Guru

Joined: Feb 2004

Posts: 1,873

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From: Phx, AZ

ICP code.

Jan 21, 2006 | 02:51 PM

jtharvey

Lead Driver

Joined: Oct 2004

Posts: 7,413

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From: Columbia, MO

I think it's probably an overboost code too. With my Predator, I don't usually run into and ICP code, but I have. Usually the culprit was an overboost code. The regulator that strokin showed is the way to go. I recently switched from the blow off valve to a regulator, and my boost is more stable, not the spikes in boost pressure that the blow off valve gave. I've got a 6-gun that reads the MAP sensor as well as a standard mechanical boost guage so I know the boost that I'm acutally running. I've adjusted my regulator so the truck sees only 23lbs of boost at the MAP sensor. It triggers the SES light at 24lbs. With the regulator the boost that the MAP sensor sees builds right up to 23psi, then it stops. Where as with the blow off valve, it would got up to about 20-22psi, then drop down to 18psi when the valves opened up. Now, it's able to see more boost, so it gives more fuel, which results in more power, and still no SES light.

But, pull the numbers and descriptions of the codes with your Predator, like was previously stated and post them here. We'll be better able to help you with that information.