Hi,
I had a problem posted in May, 2008 about engine misfire cylinder 1. We had done the tune up, and unhooked battery to reset the computer. Well, now engine warning light has been flashing a few times when I would drive it and sometimes it ran really rough, I could go 45 mph, then it would straighten out. Dealership said now an error code showed up that the catalytic converter is failing. I don't want to just replace the catalytic converter if something is causing that to fail and have it fail again. Also, are aftermarket converters as good as standard Honda ones? Also, how do I tell what engine is in this Honda EX, standard shift car? Thanks.

txgreasemonkey

. Engine misfire cylinder 1--consider replacing spark plug (NGK only) and coil.
Constant misfiring could damage a converter by polluting it with unburned fuel.

. I'd buy whatever converter is the best value (price and warranty).

. Engine code is stamped on the engine block, usually just left of the exhaust heat shield.

Maraz52

We had a garage replace the convertor with an aftermarket one, and they also replaced the oxygen sensor. Wonder if the O2 sensor was the problem in the first place? Thanks for all the advice! I do appreciate all your experience and postings Txgreasemonkey

this8384

What year and model is your vehicle? Tx is right; not doing a tune up in a timely fashion could very well have damaged the convertor; however, a plugged convertor won't "straighten out" over 45 mph, as you said your vehicle is doing. Also, an O2 sensor won't cause a cylinder misfire. Do you know which codes were present when the computer test was done? Having those help a lot with online diagnosis.

Maraz52

codes 0301, 0302,0303, 0304, 1399

We replaced the ignition coil. Then got code for misfire cylinder 1 only. We replaced the new sparkplug wires and distributor and rotor with Honda parts, and new spark plug for cylinder 1 (NGK). It ran ok for about 250 miles. Then it is running rough after me driving 60 miles, when it was going 25 mph through our little town. Today, it ran rough on turnpike going 65 to 70 mph but not enough to throw error code again. Any more ideas? This is frustrating. Thanks.

this8384

The first four codes you listed are all misfire codes, pertinant to each cylinder. However, if you truly have a convertor problem it should be throwing a 0420 code, not a 1399. When you say you replaced all the ignition parts(plugs, wires, etc.), did you replace them all within a short period of time? Or did you do one thing first, drive the vehicle for awhile, and then try something else? If you didn't do it all at once, it could have caused one of the parts to fail prematurely because it was overcompensating for the parts that had yet to be replaced.

You can tell which engine is in your vehicle by a few different ways. You can check the VIN number; the 8th digit is the engine code. If your hood is original, there should be a sticker underneath it with that information printed on it.

Maraz52

HI
We replaced the wires, plugs, distributor cap and rotor first when we had the first cylinder 1 misfire. Then we got multiple misfire codes and finally a code for ignitor failing. We replaced ignitor. Continued to misfire. We put Sea Foam motor treatment in gas twice. All this time, intermittent misfire and sometimes engine warning light would flash. Took it to dealership and they said it was cylinder 1 misfire, happened at 500 rpm, which was when I first started car that morning. They suggested replacing sparkplug wires but we didn't at that time. A few days later, another engine warning light. Took back to dealership and they said a code showed up for catalytic convertor was bad and that was causing my problems. I said I don't think so.

Took it to a local repair shop after they promised to look into it. They had it 2 days and said it must be the catalytic convertor since nothing else showed up. I said go replace it, they did with aftermarket one. And they also replaced the O2 sensor then, one by cat. convertor I assume. Car ran great for 6 wks. Then it started having subtle misfires while I was driving at highway speeds, then got to doing it at 35 mph also. Finally engine warning light came on. Took it to AutoZone and code read cylinder 1 misfire. I went to Honda dealership and bought their sparkplug wires, distributor cap and rotor, and 1 sparkplug (NGK) from them for cylinder 1. Worked great for a week. Now subtle misfire at 65-70 mph at turnpike speeds, then misfire driving thru town at 35 mph but no warning light. This morning engine warning light flashing after starting it in driveway. Hubby drove it to work with it flashing. He didn't notice a misfire while driving but warning light flashed.

Engine is 1.6 liter, 1998 Honda Civic EX with 5 speed manual transmission.

Maraz52

Oh I forgot we replaced the ignition coil right before I bought the last plug wires, spark plug and distributor cap/rotor.

this8384

This is a stupid question, but I assume you did properly gap the spark plugs before installation? Have you checked the wires to make sure that they weren't routed improperly and are being rubbed through from vibration as you go down the road?

Maraz52

Hi
Hubby checked the gap and it was within specification he said. Wires are properly attached, we double checked that already. They are fitting snugly and are in the guide things which come with the wires.
Car works fine for a short time when we do these repairs. Just no real answer. We haven't replaced the distributor yet. Problem seems to come back to misfire cylinder 1 most of the time.