Mechanics

MISFIRE CYLINDER 1 CODE AND NOW CATALYTIC

1998 Honda Civic

Engine Performance problem
1998 Honda Civic 4 cyl Front Wheel Drive Manual 129, 23 miles

Hi,
This started with car almost stalling in Nov, 2007 when I was pulling into parking space. We changed fuel filter. Seemed to run ok until May, 2008. Then code of misfire cylinder 1 started. Next it was misfire on all cylinders, ignition module failure. We have replaced fuel filter again, $10 spark plugs, $60 wire harness from Auto Zone, replaced ignitor from Auto Zone. Oil was changed out with 10W40 last few times, instead of 5W30 per husband thinking higher miles needs this oil. Engine warning light has flashed a few times when I am driving. Engine sputters and will not go over 45 mph at times, then starts running fine. Problem is intermittent until now. Dealership said error code first time they checked was misfire cylinder 1 and I needed to buy their wire harness. Now they said catalytic converter is failing. I am afraid to replace catalytic converter and still have underlying problem that will cause it to fail again. Also we have put several cans of SeaFoam in it and even 2 gallons of racing fuel in to clean out gas.
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Maraz52
July 19, 2008.




If the converter is clogged it will have these symtoms, you can have a backpressure test done by removing an 02 sensor and using a pressure gauge to read the exhaust pressure, if it's more than 1-2 PSI the converter is restricting exhaust flow. A vacuum gauge tapped into the intake manifol will do the same, hook it up reading should be 18-22 hg, and it should hold steady, if it starts to fall, exhaust is restricted.

Merlin2021
Jul 19, 2008.
We did replace catalytic convertor and O2 sensor, aftermarket parts. Worked good for 6 weeks, then misfire cylinder 1. We then replaced ignition coil. Still misfiring. Put 44K engine cleaner in gastank. Still misfire. What is next?
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Tiny
Maraz52
Oct 4, 2008.
Tell me ALL new parts and testing thats been done.

Merlin2021
Oct 5, 2008.
New parts: NGK plugs, Honda plug wires, Honda distributor cap and rotor, aftermarket catalytic convertor, O2 sensor by catalytic convertor, aftermarket ignitor, aftermarket ignition coil.

Testing shows cylinder 1 misfire occuring just after start of car, about 650 rpm, misfire happens at highway speeds too. Dealership had told me code for catalytic convertor also.
If it misses bad enough, codes for misfire cylinder 1, 2, 3 and 4 also.
It had a code for ignitor failing earlier. That is why we replaced the ignitor.
We put in SeaFoam several times in gas, and last time used a can of 44K we bought from a car repair guy.
Friday, it was running slightly rough at start and at highway speeds but no engine codes. I started car Sat morning to go home, and it immediately ran rough. Engine warning light flashed. I drove a few miles sometimes only able to go 40 mph, stoppedm turned off car and waited. Restarted the car and light wasn't flashing. Drove home, with occasional rough running at highway speeds. I haven't checked the codes yet this time.
Persistently a code for misfire cylinder 1.

Tiny
Maraz52
Oct 5, 2008.
Before we had all the problems, back in Oct, 2007, we had a local garage replace the hoses. He said since he had it apart, he could replace timing belt. I was not sure if it had been done since I had bought it used. So he replaced it. I don't think he replaced water pump.
Also had the belts replaced. We had a sound of belt slipping. Had that sound a few times after he replaced the belts also. Then sound quit. We live in Ohio. This car came from snow belt of Cleveland, so there is a lot of corrosion on motor.

Tiny
Maraz52
Oct 5, 2008.
NOTE: If DTCs P0131, P0132, P0171, P0172, P0335, P0336, P0401, P1359, P1361, P1362, P1381, P1382, P1491 and/or P1498 are displayed, repair these DTCs first. Listed DTCs do not apply to all models.
DTC P0301-P0304 - CYLINDER MISFIRE DETECTED
If DTCs P0301, P0302, P0303, and/or P0304 is set, check for: A fuel injector that is clogged or, leaking fuel or air.

An open or shorted fuel injector circuit.

Spark plug carbon deposits, fouling or other malfunction.

Ignition wires open or leaking.

A distributor malfunction.

Low engine compression.

Let me know what you find.

Merlin2021
Oct 6, 2008.

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