Hello all! New to the forums. I've recently had a problem with my 1993 Accord with a strange exhaust note. It sound like it's missing and it's losing a lot of power. It did have an exhaust leak which I fixed by replacing the exhaust with a Amazon special.

So it's got headers all the way back, brand new exhaust and the strange note is back. But it's only under power. During engine braking it sounds normal. It had been working normally for a few weeks before going back to this exhaust note like there's a leak somewhere. All the bolts have been tightened up and double checked. All the joints were sealed with Copper RTV on installation. So there appears to be no leaks.

The check engine light is also on, last time I scanned it I got an error code about the O2 sensor so that was replaced with the exhaust. I'm seriously considering replacing the ECU entirely to see if that can clear up the low idle and check engine light.

Is there any special procedure for replacing the ECU on these?

Thanks so much guys!

 

I have absolutely no idea what "strange note" and "exhaust note" are.

It's a header not headers. An exhaust manifold is singular, so is a header. Exhaust manifolds are plural, and so are headers.

RTV will never seal an exhaust component, I don't care what color it is. Use a real metal gasket.

 

It sounds more like a lumpy cam than a 4 cylinder honda. Like it's misfiring 1 cylinder.

Yes, I'm aware of that I just type headers as a matter of course. Not because I actually think there are 2 headers :D.

I used both, it's was a $275 exhaust kit engine block all the way back. I RTV'ed everything lol.

 

Being a '93 the ECU does not have a misfire code system.
What is most likely happening is you have a misfire, the fuel gets dumped into the exhaust, the O2 gets flooded, ECU knows there is something wrong but the only sensor that shows a problem is the O2 sensor is out of whack. Bing. O2 code.

Find the misfire problem.
If you still have the EGR system hooked up verify the EGR ports are clear, all of them.
If you have bypassed the EGR, verify the ECU has been retuned. Otherwise you will have a misfire at part throttle cruise.
Pull plugs and verify the are all showing equal signs of correct mixture. Verify continuity/resistance of the plug when they are hot. (thermal failure will not show up on a cold plug)
Pull plug wires and verify wires are within resistance range. Again verify when hot warm.

I've had new plugs and new wires be faulty from the factory.

 

interesting. As far as I know the EGR is all hooked up, other than the exhaust i put on it's stock.

What's pissing me off is it's acting the same as when I had a hole in the exhaust.

https://www.amazon.com/clouddrive/sh...hare_link_copy

I'll have to get a video of what it's doing now later.

 

Here's a video of it at idle. I'll get one driving around later.

https://www.amazon.com/clouddrive/sh...hare_link_copy

 

And the video of it driving.

You can hear the echo off the fence. It sounds more like a V8 than a 4 cylinder but sadly does not drive like one lol.

 

If you are hearing excess noise its likely you have an exhaust leak. Use seafoam to find the leak, white smoke will come out somewhere from the exhaust manifold to through the exhaust. Make sure when you pour some into the brake booster only pour in a tiny amount at a time and do it on a cold start when the car is idling at 1500. As you pour a tiny bit in, check for leaks, repeat.

When you tighten exhaust crush gaskets you must tighten them lightly in several stages to help prevent leaks.

 

Good idea! I've got a bottle of that laying around somewhere. Where's a good hose to introduce it?

 

brake booster