Black & Green modding thread (1998 Civic DX Coupe base)

[California98Civic]

Originally Posted by Chrysler kid

...
Considering you would want to superheat your exhaust to run leaner, you can safely assume at your mileage that since you are not suffering from loss of power, that the catalytic converter material has broken internally. ...

I don't know. The code is intermittent. I get it. I clear it. A few days or a week later it maybe comes back. I think it has been a week now and couple hundred miles without it lighting up. If the CAT were as damaged as you are suggesting, wouldn't the failure be more complete? I think maybe my head gasket failure bummed up the CAT. Maybe it is clearing itself over time? Ever seen that happen?

[19bonestock88]

My Saturn had an O2 related code that would come up from time to time (something about response time or something), that’s been completely gone for the last 20k mi... it also recently had a P0420 that I haven’t seen in a while...

[jcp123]

Cat codes can drive you nuts. I went a bunch of years in my Echo with a bad cat. If I cleared the code during summer on the freeway, it might not come back until I got off the freeway. But if I cleared it at any time during winter, it would come back immediately. If it's a P0420 the cat probably is bad; if it's an O2 code, it deserves more testing (doesn't take long).

[California98Civic]

Moving very slowly because of work and family duties, but I stole some daylight time just now to rerun some light transmissivity tests on the clear tint I am experimenting with.

I figured out the mistake I made in post #405 above. I moved the light sensor. Any change in angle to the sun changes the reading. So I did the test again.

Using my tablet's built in light meter and an app to read it on screen, I find a 28% reduction in visible light through the clear tint versus the bare windshield. Seventy two percent transmission is acceptable. My side window tint allows only 38% light transmission into the car.

Of course, heat transmission is a different bear. I have no tool for measuring that.

On another note, I creased part of the tint during the test. Good thing I bought more than twice what I need. I knew I would eff up some.

[Xist]

Did you only replace the head gasket? I have read that Honda originally had a kit, but they discontinued it a while ago. I found the kit while looking for the gasket itself. Instead of looking around Majestic further, I came back to look at what you did.

[California98Civic]

Originally Posted by Xist

Did you only replace the head gasket? I have read that Honda originally had a kit, but they discontinued it a while ago. I found the kit while looking for the gasket itself. Instead of looking around Majestic further, I came back to look at what you did.

I bought the head gasket and cam shaft seal from Honda (no kit). And I bought the exhaust mani gasket and intake mani gasket from O'Reilley. The head gasket is the most important one, and I am way wicked grateful that I bought OEM instead of one of the knock offs. Buy Honda for important parts.

[Xist]

Did you reuse the head bolts? How come you replaced everything else?

[California98Civic]

Originally Posted by Xist

Did you reuse the head bolts? How come you replaced everything else?

Yes I reused the head bolts, but if you do that, you must create a numbered template of their positions in the head. Get a piece of cardboard and an indelible ink pen and make holes that represent where the bolts go. As you pull the bolts out put them in the corresponding numbered holes in your template.

I replaced the other gaskets and oil seal to avoid leaks. They are all one-time use kinda things. It prolly matters little with the exhaust mani gasket. But the intake gasket you have to replace. A leak there will cause the engine to run badly.

Also, MAKE SURE a pro machines the head to make sure it is level and that you clean the block's deck really well. It will have caked on gasket material. Look up safe procedures for using a blade or pads to really clean all the remnant gasket material or your new gasket will leak for sure. My one area of worry about my job is the possibility that I maybe did not get the block clean enough. Time will tell.

[Xist]

Which gaskets are metal? Many say that metal ones are reusable, although I replaced my EGR gaskets, while I have reused other metal ones.

[California98Civic]

Originally Posted by Xist

Which gaskets are metal? Many say that metal ones are reusable, although I replaced my EGR gaskets, while I have reused other metal ones.

The cam seal was a polymer of course. The intake gasket was some type of pressure-formed composite metal and it definitely must be replaced since it squeezes into place. The exhaust gasket was a contoured metal sheet. I have reused it before, but I took my machinist's advice to replace it this time.