normal after header install?
Thread Starter
Launching!
Joined: Mar 2003
Posts: 207
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From: kansas
normal after header install? I've noticed a sharp decrease in gas milage. Before headers I could go about 200 miles before I reached the 1/4 mark. Now I only go about 130~160 miles before the 1/4...
TECH Senior Member
Joined: Jun 2003
Posts: 9,339
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From: NYC metro area
Re: normal after header install? Check your ign wires. That seems like a lot of lost gas mileage for headers. Are you running longtubes? If so, check and make sure you haven't melted a wire, thus causing a misfire.
Thread Starter
Launching!
Joined: Mar 2003
Posts: 207
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From: kansas
Re: normal after header install? Yeah, they are long tubes. I have firesleeves over the wires... is it possible to melt the wires even with them on? The sleeves are rated at 500 degrees. Would tuning have any possible effect on this? My idle "surges" from 500 to 600 to 500, ect... rpm and when I hold down the brake (auto) the feels like the brakes won't hold (kind of like in a manual when you let up on the clutch to fast and you put too little gas, you get that massive vibration just before the car stalls). It even "surges" when I'm driving. All of a sudden I get is burst of speed without have to press the pedal down any further.
TECH Resident
Joined: Jun 2002
Posts: 943
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From: Houston
Re: normal after header install? that sounds like a burnt wire to me. it will surge pretty bad at idle, shake, but when you give it gas, its a slug until the rpms get up a little then it feels like it gets a boost of power. Yes, the plug wires can burn with heat sleeves. Mine burnt with heat sleeves because the wire was still laying on the header with only the sleeve between the two. Just make sure there is a lil gap between the sleeve and the header pipe and you shouldnt have any problems, just as long as the plug wire isnt laying directly on the part of the heat sheild that is touching the header. Headers increased my gas milage, not the opposite 
Staging Lane
Joined: May 2003
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Re: normal after header install? replace your 02's since I think you either touched the sensor with your oily or dirty fingers or wait til nightfall and pop the hood and look for fireworks, yes, you will ruin an o2 sensor by touching it, it is due to the design of the metal that gets hot for the reading and oil and/or plain dirt will throw the readings off.
TECH Resident
Joined: Jun 2002
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From: Houston
Re: normal after header install? I have never heard of the O2 sensor going bad from touching the bladed shield around it. I handle them all the time, even dropped it a few times, and it works fine for me. Im not saying it couldnt happen, but look at what you had to disconnect, re-reoute or re-assemble to do the header install....plugs, plug wires, and O2 sensors. If it was the O2 sensor, it would be running like complete *** and there would be no power anywhere, it would studder all over the place. Wires on the other hand get burnt all the time on a header install and his symptoms are those of a burnt plug wire(idling erratic, kinda rough on the bottom end, but pulls smoother once the rpms are up). Are you getting an SES light at all? If so, is it solid or is it flashing? Hook up an autotap and check the misfires on all the cylinders and that will let you know if there are any burnt plug wires, and also check the SES code and it will tell you if its an O2 sensor or not. I bet money on the plug wire though.
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TECH Senior Member
Joined: Jun 2003
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From: NYC metro area
Re: normal after header install? Well, whatever it is, it definitely sounds like a misfire of some sort, Check the wires and the opti. I guess it could be an O2... I'd agree with Gangly, though.
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Launching!
Joined: Mar 2003
Posts: 207
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From: kansas
Re: normal after header install? Things just get more and more complicating. I had some time yesterday to check underneath the car. The passenger side is leaking, where the i-pipe meets the y-pipe on the driver's side, those pipes are not aligned properly (lot of air escaping) and on both sides the pipes touch the underside of the body. The situation you described, Gangly, is exactly what I experience. I don't get any lights... except the airbag light. The SES light doesn't even come on at all (even when I start the car) so I think that may be a burnt bulb. In addition, no one is touching the exhaust because I'm running without cats. I think I'll put them back on just to have someone do all this for me. With work and school, I don't have the time to deal with this added stress... This is so much crap!!! Oh, and I don't have an autotap. Where can I go to get the computer scanned?
Thread Starter
Launching!
Joined: Mar 2003
Posts: 207
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From: kansas
Re: normal after header install? Well, this morning I had a shop fabricate some new pipes for me. He basically told me the clamps holding the exhaust pipes were crap and with the way the pipes were made, it would be impossible or nearly impossible to bend the pipes to they wouldn't bang against the floor body. So, now I have what looks like a huge y-pipe in place of the off road pipes and orignial y(from headers to cat back) and it's welded into place. The good news is that all the leaks have stopped and I have no more banging issues. I even got additional clearance. Bad news, the sound softened up a lot! (The noise level went from 
to 
) I was disappointed 
in this but I'd rather sacrifice sound than have leaks and banging. All the noise comes from the exhaust now, like I only have a cat-back. I haven't looked at the ignition wires yet, but someone told me that I might want to check the plugs as well as the wires. Is it possible that the plugs are causing the misfires too? I hope not. I had both replaced when I changed out the headers. Now I have to buy (possibly) wires and plugs... How have you guys (the ones with aftermarket headers) set up your wires? I'm thinking to using a wire kit sold at Thunderracing that can reroute the wires over the valve covers.
to ) I was disappointed in this but I'd rather sacrifice sound than have leaks and banging. All the noise comes from the exhaust now, like I only have a cat-back. I haven't looked at the ignition wires yet, but someone told me that I might want to check the plugs as well as the wires. Is it possible that the plugs are causing the misfires too? I hope not. I had both replaced when I changed out the headers. Now I have to buy (possibly) wires and plugs... How have you guys (the ones with aftermarket headers) set up your wires? I'm thinking to using a wire kit sold at Thunderracing that can reroute the wires over the valve covers. TECH Resident
Joined: Jun 2002
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From: Houston
Re: normal after header install? i routed mine along the side of the block behind the headers and have had zero issues since then. Generally, the plugs dont foul out on LT1's unless you have a power adder or the 02's went out. Just check the wires first.
TECH Senior Member
Joined: Jun 2003
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From: NYC metro area
Re: normal after header install? Gangly, you wouldn't happen to have a pic of that route, would you? I sleeved the wires but fried a few more this weekend, so she's missing again 
You think any of my plgus could have fouled due to the Vortech?
You think any of my plgus could have fouled due to the Vortech? Thread Starter
Launching!
Joined: Mar 2003
Posts: 207
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From: kansas
Well, finally got the plug wires replaced and everything is running great! I ordered a wire kit from ThunderRacing that allowed me to run the wires over the valve covers. Thanks to all that have offered advice and special thanks to Gangly for reponding to my post and helping me out.
TECH Resident
Joined: Jun 2002
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From: Houston
Good Deal man, glad to hear it was something simple 
Supermario...i dont have any pics of the plug wire setup. I will be getting a digital camera here pretty soon I hope, and once I do, I will show you pictures of how I ran the plug wires.
Supermario...i dont have any pics of the plug wire setup. I will be getting a digital camera here pretty soon I hope, and once I do, I will show you pictures of how I ran the plug wires. TECH Senior Member
Joined: Jun 2003
Posts: 9,339
Likes: 3
From: NYC metro area
Okay, cool. I've been having a hell of a hard time with wires, and between school and work I don't even have the time to do something as simple as wires I've only been in college for 2 months, and already I can't wait for the summer so I can get my car running better.
I've only been in college for 2 months, and already I can't wait for the summer so I can get my car running better. 
Teching In
Joined: Oct 2003
Posts: 13
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From: Waco, TX Denton, TX Navasota, TX
Aren't LT's supposed to SAVE you gas mileage?!?!
I do know the lead foot comes into play right after LT's are installed, but if you continue to drive 'economically,' if that's even possible in these cars, aren't we supposed to see gas saved through the addition of LT's...?
I do know the lead foot comes into play right after LT's are installed, but if you continue to drive 'economically,' if that's even possible in these cars, aren't we supposed to see gas saved through the addition of LT's...?