: Re: Headers and the DAMN check engine lite

That's all easily verifiable by checking the O2 crosscounts:
Also the block learn and integrator.
My feeling is: Your header gaskets aren't sealing at the head flange
correctly. (Ad do most headers, especially if they have a bead of weld at the pipe, to seal at the gasket. causing a vortec, and drawing in air to cause a lean signal at the O2 Sensor.
Now how the hell is that for a theory?
I've seen it, and fixed a few.
If that is in fact the problem, here's the fix! remove the headers, get a good bodyman with a flat (Sharp) metal body file. Have him screw it to a piece of 2X4 board.Have him screw it on the edge of the board, and start filing from one end to the other. If he didn't check it with a good straight edge first, you'll see all the low spots miraculously not get touched by the file.
Ten about an hour and a half after, the first header will be done!
Voila, no more poor fuel economy and shitty performance.
I hope this helps?
Refinish King
Subject: Re: Headers and the DAMN check engine lite Date: Tuesday, June 29, 2004 11:05 AM
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.
--
Mad dog



"Chuck H." < snipped-for-privacy@charter.net> wrote in message
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Yes, i agree with your "theory" The actual mixture can be read by using a DVOM set to the millivolt range tapped into the signal lead of the 02 sensor: 0-.33V=lean, .34-.69V=stoichiometry or lambda1 and .7-.99=rich. different sensors will give different output voltages for the same air/fuel mixture, these figures are close representations of the actual voltages output from a lambda sensor which vary with fuel mixture, exhaust gas temperature,humidity,altitude, atmospheric pressure, etc etc. O2 sensors wont function correctly until the EGT is at least 600 F. that is why heated sensors are far more accurate than non-heated sensors, especially at idle or when coasting.
he didn't mention hearing a tick,tick,tick indicative of a exhaust leak at a hedder flange so i did'nt think to explore the possibilities of such a condition (my bad)
-- Mad Dog

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Sometimes they don't give off the tick sound:
That's why I mentioned it.
Upon diddling, to show the ECM is working properly, with a good and strong O2 sensor. the reading can go low as 0.0 milivolts for a couple of seconds, then go to as high as1.5 milivolts. (As I said, with a good strong sensor)
When you've been around this shit long as we have, I guess we've seen it all?
Refinish King

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Why not just tell him to draw file it? When ever my father taught me that one I thought I'd cream my pants! I pretend to know what I'm talking about with cars - but I can certainly fabricate! -- "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

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It's a hell of a lot easier to find:
An 18" body file, than an 18' draw file?
The shorter the file, the more chance of making it more uneven. The ultimate fix would be a 32" top but called a 64" belt sander, or 48-96".
But hard to find, in my wood shop I have a 24"-48", and the header would hang off a bit, not that I would ever put metal on it anyway.
Refinish King
I'm sure your father and my father would have been able to do it with short files though. My father used to straighten warped carb bases on the most uneven places, and when checked with a straight edge, perfect!

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Well guys, it seems I did leave allot out, sorry. The first thing I think I need to say is "thank you all for trying to help",,,,,the second is,,,,,lol,,,about myself, as I am a machine shop owner who is 46 tears old and just let the 70's hot rodder in me put the headers on the truck anyway,,,,lol,,,,told the wife it was build the shop truck up a little or get a dirt bike to play with,,,,hmmmm she said, I've seen your medical records from racing moto x so how much is the truck gonna run,,,,,,,lol,,,,that's how all this came about see,,,,,and as far as the headers being sealed to the head goes, I machined the heads myself and had another shop check them for me as we all know you never see your own mistakes hardly. I also if memory serves right took about .020" off each flange of the headers and was impressed with how flat they were from the factory. Please continue to give me suggestions at what to look at next as the code it throws is an oxygen code. And yes you that wonder if I am the one who makes the xdrilled rotors I bragged on, you are correct,,,,I know , I have no shame,,,,bad boy I am,,,,,lol,,,please any of you having trouble there go check my web site as I do the best job in the world and sell all over the world on xdrilled and slotted rotors. Thanks again for any help guys
--
Chuck Hembree
Hi-Tec Tool, Inc
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Um, I just use a flat bastard file to draw file with. I didn't know they made "draw files". I used it to make an 8" tanto-style knife out of an annealed file and hardened/polished it etc... One of the best knives I own! Stick it through a car roof and cut tomatoes with it...
-- "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

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A draw file:
Like a draw knife for wood.
Refinish King

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Yup, a draw file. A file held sideways and drawn towards the body....
-- "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

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I guess the file and 2X4 fix for the header flatness might work if you live in the back woods somewhere, I took my new Throleys to an engine rebuilder guy with a belt sander. Both perfectly flat in 10 minutes.

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Not that I live in the backwoods!
I'm a bodyman, and a metal fabricator, that just doesn't happen to have a belt sander in his metal shop yet. The metal file does a nice enough job when you straighten a car, that all you do is primer and paint.
Refinish King

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