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I installed an SPD y-pipe shortly after buying my 2002, and have the dreaded flutter pretty badly. When cold, for the first 30-45 seconds it sounds like an exhaust leak but only in the 2,000-2,500 RPM range. Also, when warmed up, if pulling a load uphill in the 4,000-4,500 RPM range I hear it. I have been reading some old threads on the topic, and some have suggested deleting the cat will fix this issue. That, or installing headers. Can anyone confirm either of these ideas?
Talking about intentionally removing emissions control equipment is frowned upon because the tyrannical EPA has been imposing fines and sending people to prison for such things recently (even though there is no law being broken, the clean air act is just that, an "act", not a law that our elected officials ever voted on, it was imposed upon us by unelected bureaucrats but somehow carries the weight of law).
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Talking about intentionally removing emissions control equipment is frowned upon because the tyrannical EPA has been imposing fines and sending people to prison for such things recently (even though there is no law being broken, the clean air act is just that, an "act", not a law that our elected officials ever voted on, it was imposed upon us by unelected bureaucrats but somehow carries the weight of law).
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It is illegal to remove the catalytic converter for all on-road vehicles (street use). It can be done but I just want you to be fully informed in your decision. Be aware if you delete the cat on a gasser, it will throw check engine light error unless you install an ozygen sensor spoff to fool the computer to think the cat still exists and the O2 sensor is reading withing spec.
Technically, an Act is law. In the case of the Clean Air Act, it was congress authorizing the EPA to define and uphold the law.
Definition of Act
In legal terminology, Act is used to mean the statutes approved by the parliament. Originally, it is a bill, which when passed by both the houses through a specific procedure, turns out as an act. Act either creates a new law or make amendment in the existing one. An act focuses on the particular subject and contains various provisions relating to it.
Source : Difference Between Act and Law (with Comparison Chart) - Key Differences
The Clean Air Act is the law that defines EPA's responsibilities for protecting and improving the nation's air quality and the stratospheric ozone layer. The last major change in the law, the Clean Air Act Amendments of 1990, was enacted by Congress in 1990. Legislation passed since then has made several minor changes.
Source: Clean Air Act Text | US EPA
The EPA doesn't get to make laws , and congress can't just delegate that authority to them. That's the whole point of a Representative Republic, we're supposed to elect people to represent us in the body of lawmakers.
But without turning this into a further civics discussion, it still stands that openly discussing the removal of emissions control equipment in these style forums in now frowned upon (which is also kinda a 1st amendment infringement too if you think about it, but I digress) .
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I installed an SPD y-pipe shortly after buying my 2002, and have the dreaded flutter pretty badly. When cold, for the first 30-45 seconds it sounds like an exhaust leak but only in the 2,000-2,500 RPM range. Also, when warmed up, if pulling a load uphill in the 4,000-4,500 RPM range I hear it. ....
I installed an SPD Y-pipe on our 2002 Limited 7 years ago and have had no issues with flutter.
Are there any other mods to the exhaust?
Our exhaust was factory stock until the pipe bend in front of the muffler rusted and broke.
The break in the pipe bend was toward the center and hard to see from just looking under at the exhaust.
Water vapor collects in the upward bend just before the muffler and rusts the pipe over time.
Maybe you have an exhaust leak and the more efficient flow with the SPD makes a leak more noticeable.
Replaced the pipe/muffler with a Walker 54485 and have not noticed much difference.
I guess anything is possible - totally stock 210,000 mile exhaust otherwise. It was noticeable immediately after the SPD install and has stayed dead reliable the entire time I've owned the vehicle. 2,000-2,500 RPM on a cold start will make it flutter - always gone after 45 seconds or so. If you start it and let it run a minute or so before driving it will not do it. Depends on how long it sits between start ups as to whether it will show up again or not. If the exhaust has a chance to completely cool down, then it will do it again. Does not act like any exhaust leak I have ever experienced - sounds like a mixture of an exhaust leak and ticking lifter, but not really exactly like either noise - just the closest sound I can compare it to. No visible signs of an exhaust leak, though I know that doesn't always mean much. All my manifold studs are at least visible as well, though I also know some could be broken and just hanging in place. Doe not cause any drivability issues, just annoying.
.... It was noticeable immediately after the SPD install and has stayed dead reliable the entire time I've owned the vehicle. 2,000-2,500 RPM on a cold start will make it flutter - always gone after 45 seconds or so. If you start it and let it run a minute or so before driving it will not do it. Depends on how long it sits between start ups as to whether it will show up again or not. If the exhaust has a chance to completely cool down, then it will do it again. ....
Maybe there is something the computer is adjusting when the engine is cold, then changes after 45 seconds or so.
Can you tell if the flutter goes away at a regular time after startup or when the engine reaches a certain temperature?
I have a ScanGauge II mounted on the dash which will show the engine temp the computer uses to control things.
The dash gauge is not very accurate and I think is driven by the computer.
There are probably newer/better/cheaper OBD2 units out there nowadays.
Maybe the computer changes the air/fuel ratio when the engine reaches a certain temp or something like that which affects the flutter.
I can't say there was any big change when I installed the SPD Y-pipe, certainly no gain in MPG.
It just made me cringe anytime I looked at the old exhaust Y intersection.
It did seem to start easier and accelerate a bit smoother/better.
Best way to rule out any possible exhaust leak is run your hand around every component just after start up, while the exhaust is still cool enough that it won't burn your hand. Feel for any exhaust leak. It's easy to feel the air pressure difference, even on a small leak. Start by the headers and move down towards the cooler end of the system.
Your explanation of the sound makes me think it may be a shroud rattling somewhere. You can always check the transmission torque converter cover at the lower front of the transmission case. Also, there's a metal heat shield attached to the underside of the body near the back of the catalytic converter. You'll see the silver mat and at the rear of the mat is the shield, It's about 6"x6" and bolted on. Make sure that isn't rattling.
.... Your explanation of the sound makes me think it may be a shroud rattling somewhere. You can always check the transmission torque converter cover at the lower front of the transmission case. Also, there's a metal heat shield attached to the underside of the body near the back of the catalytic converter. You'll see the silver mat and at the rear of the mat is the shield, It's about 6"x6" and bolted on. Make sure that isn't rattling. ....
This reminds me, also check the heat shield cover around the cat.
Mine started rattling and stopped after putting 2 large HVAC clamps around the shield to hold it tight against the cat shell.
Yeah, I just slid under it to check things out - all the heat shields and TC cover seem tight. I did, however, find that the exhaust clamp just forward of the converter had broken and was just sitting on the pipe. I pulled that out, hoping it would make a difference, but no the noise is still there. I was trying to think of what it sounded like exactly, and it came to me. It sounds like a baseball card in the spokes of a wheel. No joking. Just a rpm - dependent clicking sound. Almost like I should be able to find something jammed up in the suspension except that it only happens in certain conditions and rpm.
Even though it started after Y pipe install and you’ve checked all exhaust connections, have you ruled out the heat shield on the front of the transmission? Mine had an annoying metallic/flutter rattle at ~2000 RPM especially under a load.
I added some double sided tape (between shield and transmission) almost a year ago and it’s been quiet since. Others have physically bent the shield with good results too.
I see what you mean from the pictures - thanks. I slipped underneath and took a look. I can't say the heat shield 'feels' loose at all, but I can see how maybe that space between the two mounting bolts could contact under certain conditions and rattle. I created a rubber wedge and sandwiched it in there so that there is no play at all and no metal contact. I'm going to wait a while before road testing it so that everything is as cold as possible for accurate results.
Yeah, I just slid under it to check things out - all the heat shields and TC cover seem tight. I did, however, find that the exhaust clamp just forward of the converter had broken and was just sitting on the pipe. I pulled that out, hoping it would make a difference, but no the noise is still there. I was trying to think of what it sounded like exactly, and it came to me. It sounds like a baseball card in the spokes of a wheel. No joking. Just a rpm - dependent clicking sound. Almost like I should be able to find something jammed up in the suspension except that it only happens in certain conditions and rpm.
Is this where some people suggest a spark plug leak, from a loose plug?
Is this where some people suggest a spark plug leak, from a loose plug?
The vehicle does have 210K.
Have the plugs ever been changed?
Pull one plug, it hopefully is not an OEM - AGSF22WM.
Even if not, if you don't know how long the plugs (Motorcraft SP479) have been in there torque them to 25 ft/lbs, soon.
Or replace & toque to 25 ft/lbs.
If you start getting a misfire at idle, try changing the boots/springs, especially if they look original.
The coil part of the COP assembly will last a lot longer than the boots, which are available separately.
The guy I bought the truck from 7 years ago was a Ford Tech, and had just done coils / plugs recently. Truck has a complete Carfax too of it's cushy life in Southern MS. Still would be my luck that it would launch a plug now, after 7 years of hanging on for dear life. That being said, now I'm paranoid and I will probably check them anyway.
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