Well, I guess it's getting the helicoil, what's a fair price for a shop to do this job?

It's too risky for me to do myself.

I re-tightened the bolts where the leak was coming through, and I cleaned it best I could with some 409 and a toothbrush. I'm monitoring to see if the carbon starts building up again. I'm monitoring the leak where the one bolt is missing, I don't see any carbon coming through yet. In fact, when my dad put the rag on the tailpipe I only saw stuff fizzling from the area where the studs weren't broken. We'll have to do this again and see if anything is coming through.

A new gasket was installed, right? Put a straight edge on the manifold after you take it off to check for flatness.

I cleaned off the carbon that was coming out of the manifold, tightened the bolts and I don't see anymore carbon coming out yet. It's been a little over a week and I still see the silver.

I got a replacement 02 sensor for the upstream and I installed it today. I'm not sure if the code clears itself, so I went ahead and cleared it manually from the ECU.

I can already tell it's improved my cars performance. The tachometer seems to move a lot steadier and I believe it's shifting sooner at lower rev's. Even if it doesn't clear the code I'm glad I replaced it, the other one had been in and out of the exhaust 5 or 6 times, and it was bound to get stripped after awhile.

Well, code came back today.

I'm thinking about sea foaming the car. If I put sea foam down the intake to the throttle body, will that clean out my catalytic converter?

The can of sea foam says it will clean out the cat, but after putting the whole can in my tank, as directed with proper ratio of 2oz to gallons, I don't see a difference yet. Since it's been affecting my gas mileage and I know for sure now the upstream 02 sensor is good, this must mean it's my catalytic converter getting stuffed up.

Maybe I could just take a hose and run it up my exhaust to where my cat is and apply the sea foam. Or perhaps I could park on a slope at the right angle and pour it down my exhaust pipe, let it sit there for a couple hours and see if my code gos away.

Question: If the cat is causing the code, and I fix it, will the code go away automatically after a few days?

You can clear the code by disconnecting the battery or pulling the ECU backup fuse. Then see if it comes back. The CEL will go away by itself, but the error is still stored.

Not sure if that's a good way, trying to pour it into the exhaust pipe. Besides, you won't get a hose directly through the mufflers.

Another can, sucked into a vacuum hose while the engine is running, is probably the way to get it into the cat.

http://static.ddmcdn.com/gif/muffler-cutopen.jpg

Looking at a diagram of the inside of a muffler, I see now why it can't work.

I used to have a giant hole in my exhaust pipe, I should have attempted this then! (hah).

<strike>Perhaps I could drill a small hole in my exhaust pipe, pour it in close to the catalytic converter?</strike>

I can't believe it took me this long to think of it, I added the sea foam into the port where my oxygen sensor was on the exhaust manifold. It smoked like the dickens going down the road, it was pretty funny watching the car behind me stay back about 50 feet.

I replaced the 02 sensor with a Bosch, not the OEM denso variety.

Do you think this why I still have the code?

I checked the manifold, straight as an arrow, no cracks or anything.


Tomorrow I'm going to replace all the spark plugs and see if that does anything. I know they are probably overdue.

Lots of people have reported trouble with Bosch spark plugs in Hondas, but I've used them without problem. I'll suggest getting NGK or Denso plugs, but not really sure if the O2 sensor would be a problem. Unless the store gave you the wrong Bosch one.

I replaced the spark plugs today. An exhilarating, yet at the same, terrifying experience worrying that the spark plug was going to break off or strip.

I replaced them with stock ones from Honda.

They looked normally worn(tannish coloration w/ slight oil deposit on the threads) and the gap was nearly down to the bottom. They were definitely in need of being replaced but show no signs of engine problems. I coated the new ones with anti-seize applied with a toothbrush.

My engine hasn't thrown a code yet, so I reckon I tightened them well enough into the block :)

I fueled up again today and checked my gas mileage. I don't know if this is a sign of that sea foam cleaning my fuel-injector or if the oxygen sensor is working, but my gas mileage is up to 24.6 MPG now. I'll keep monitoring it.