Headers and the DAMN check engine lite

This is about a 1988 350 auto 4x4 2500 Suburban. After putting on headers the damn light keeps coming on and when it does go on I can watch the gas gauge move.

Just to tell you what I have done to try and stop this. I installed a sensor that is preheated from a corvette and it didn't stop the problem.

If any of you have any ideas please share with me.

I will share with you that are having rotor problems with warping or rapid wear, get you some cross drilled and slotted from

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as mine work great. 142,000 miles now and I put them on at 11,000.

Reply to
Chuck H.
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the heated sensor will help the ECU while running in closed loop..........but installing the hedders forced the mixture over too the lean side because of the increased scavenging. the higher combustion chamber temperature may be causing some preignition which the knock sensor is hearing and then the ECU turns the light on because it's unable to compensate for the lean condition by going to full rich mode while retarding the timing. (holy crap, what a theory........huh) i don't know brother, maybe you knocked a wire somewhere that's pissing off the ECU. you could try changing the PROM chip in favor of a performance version, this would give you a fuel curve that takes advantage of the increased scavenging offered by the hedders. your guess is as good as mine friend.

Reply to
Mad Dog

How about no guesses and telling us what codes it is throwing?

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-- "Ignorance is preferable to error; and he is less remote from the truth who believes nothing, then he who believes what is a wrong." - Thomas Jefferson Formerly: KJ the Lonely Grease Monkey

Reply to
GMC Gremlin

Sorry, as I should have thought of that, every time I have had it checked, they say it is a oxygen code.

preignition

Reply to
Chuck H.

Well hell, if nothing else this thread was very educational,

-- Mad Dog

Reply to
Mad Dog

This is the first time I read an answer to why my mpg. went down about

7% after I installed a Flowmaster muffler on my Blazer. Chevy wants $360 for a new stock muffler and I figure it will take about 60,000 miles of driving before it pays for itself. ;-(

brody

Reply to
brody

Are you sure that you're not driving a little more spirited with the louder muffler then you were b4 u installed the flowmaster................maybe gettin it a little mo cuz it sounds so good. come on now, tell the truth. LOL

-- Mad Dog

Reply to
Mad Dog

Hey Dog,,,I'm guilty of that, except I have headers and a flow master,,,,,,lol,,,,real nice tone,,,,,

Chuck

Reply to
Chuck H.

Most people don't realize the sound adds:

Weight to the foot, and decreases miles per gallon.

A free flowing system, actually increases mileage, due to the lower end torque improvement, and the higher range horsepower. Due to the more even combustion process.

Refinish King

Reply to
Refinish King

That's what my experience was in the "old" days, but maybe a 'puter controlled engine has other ideas.

brody

Ok, I'll admit at first that was true, but when gas went to $2.50 here I drove like there was an egg underfoot and still got worse mpg.

brody

Reply to
brody

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