I have a 1997 Honda Civic LX. A few months ago my check engine light was on and I had cylinder misfires, so I had new spark plugs installed with new wires and a few days later the Check Engine light went off. About 2 months ago I noticed the Check Engine light came back on. I went in for an oil change and they notified me that I had a broken axle boot (that wasn't urgent) and an oil leak definitely around the valve cover. They also read the codes from the Check Engine Light. Last week I installed a new valve cover gasket, and the leak doesn't seem as bad, if existing at all. Since my oil change I've been having a new issue.

When I first start the car in the morning, the car runs fine. Only when the car is WARMED up do I have an issue where the car stalls when I come to a stop. If I press the gas pedal it will not stall, but if I come to a stop it very often turns off/stalls and I have to turn the key and start the car again. It always starts up right away. When the car gets warm and I can tell that I might stall, I've also noticed that the steering of the car gets slightly stiffer. But again, when I run the car cold, it runs great. I also never feel misfiring like I did before I changed my spark plugs. The check engine light is on and here are the six codes that I got when I got my oil changed:

p0171 Air/Fuel Mixture System Lean Bank 1
p0301 Cylinder Number 1 Misfire Detected
p0302 Cylinder Number 2 Misfire Detected
p0303 Cylinder Number 3 Misfire Detected
p0304 Cylinder Number 4 Misfire Detected
and -p1300

If anyone has any advice on where I should look to detect the issue, that would be appreciated! Thanks!

 

I was curious of that too. My friend installed new spark plugs and wires and he said they were pre-gapped. Would it make sense that the check engine light did go off a week later after he installed them, but then a month later the light was back on? I figured he did it correctly just because the light went off?

 

so since every cylinder is misfiring, i have a VERY hard time thinking all the plugs are bad but, it is a good idea to make sure the proper plugs are in the engine.

P0171 means either too much air, or not enough fuel.

Have you checked for vacuum leaks or a clogged fuel filter or weak fuel pump?

 

P0171 is the CEL you should be diagnosing. Step 1 of diagnostics is to pull the CELs. You did that. Step 2 is to reset the ECU, and see what codes return. Do that next.

As for P0171 diagnostics, do you have a scan tool that can log live data? If not, we're gonna be doing some stabbing in the dark.

 

^

 

I just reset the ECU, I'll try to get the codes re-read soon.

 

I reset the ECU on Saturday and the check engine light as been off ever since, and my car is running fine. It hasn't stalled yet. I'll let you know if the check engine light pops back on. Thanks

 

Check for intake manifold vacuum leaks. You can do this by spraying some carb cleaner around the intake manifold and see if the idle surges or changes indicating a leak.

If that checks out fine test your fuel pressure.

I would also look around for an exhaust leak near or before the primary oxygen sensor.