How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask MASTER TECH Your Own Question
MASTER TECH, Honda Service Technician
Category: Honda
Satisfied Customers: 5716
Experience:  28 years of Honda training and a master Honda tech
Type Your Honda Question Here...
MASTER TECH is online now
A new question is answered every 9 seconds

2003 Honda civic engine light came on. Honda dealer cleaned

Customer Question

2003 Honda civic engine light came on. Honda dealer cleaned and replaced EGR valve and chamber, and oil pump leak near timing belt. Work cost about $1500. All seemed well then engine light came on again the next day and gave code indicating cylinder 4 was misfiring according to mechanics reader. Mechanic said it could be one of several things and that it would require a mechanic to drive around in the car while the computer was hooked up to a reader (diagnostic tool?) thing and would cost up to $2000. He did mention it could possibly be as simple as spark plug or coil. So I thought I would do that work myself before paying out so much money just to find out what was wrong. Mechanic reset the computer. I changed the spark plugs and cylinder 4 coil. Engine ran much smoother afterwards. The cylinder 4 spark plug had quite a bit of hardened greyish white dry cake like stuff built up over the spark plug's white insulated cone shaped tower that normally resides inside the cylinder head. Only this plug had that problem. I've never seen so much like that. No oil residue on any of the plugs. I thought that was probably what was causing the error. I also replaced the cars battery which were showing signs of weakness. The next day engine light was back on with same code, P1304 Cylinder 4 Misfire. At this point, after investing $2000 trying to get this car back to normal I can't see spending another $1500 on this engine. I wonder if disconnecting and replacing the battery may have caused the error message, previously eliminated by reset to return.. I don't know what best course of action is at this point.. Thanks for any help/advice you can give me.
Submitted: 7 months ago.
Category: Honda
Expert:  MASTER TECH replied 7 months ago.

Hello welcome to just answer I am master tech and will be able to assist you.

few questions for you.

has a compression test or cylinder leak down been done yet ?

can you recall the last time the valves were adjusted ?

can you look at the radiator reservoir and see if it's empty or have coolant in it and if so can you smell any type of exhaust or fuel smell ?

Customer: replied 7 months ago.
Don't know on the first two. I can tell you that the car has had normal maintenance required by Honda dealer since purchased. It did develop some kind of disappearing engine oil problem which no one seemed to find a reason why or fix; however this last time it was in with EGR issue they found the oil pump was leaking and fixed that. There is absolutely no oil on the floor where it is stored and no oil residue on the spark plugs. The radiator reservoir is full and no exhaust or fuel smell in engine compartment or inside car. I've read the description of misfire code and it seems so vague, ominous and useless at the same time. Very frustrating..
Customer: replied 7 months ago.
Almost all maintenance performed at Honda dealership..
Expert:  MASTER TECH replied 7 months ago.


the reason for asking these questions is we see on a very regular basis at my dealer is the head gasket fails and uses coolant and will set random misfire codes.

so been this is isolated to the #4 cylinder I would be suspecting a tight valve or fuel injector issue of not a head gasket.

Customer: replied 7 months ago.
I'm with you on that.. I was thinking maybe should try by adding something to full tank of gas and see if it that might help clear the injector if that happens to be the problem. If you agree, do you have any recommendation on type or brand additive to use and if we're down to valve or injector as likely cause can the car still be driven on short trips without too much concern of breakdown..?
Customer: replied 7 months ago.
This car had been sitting for quite sometime while deciding what to do with all the problems it had. So injector issue looks more likely. Although it is isolated to cylinder 4..
Customer: replied 7 months ago.
Sitting a few months.. Driven irregularly.. Thanks for your help on this..
Expert:  MASTER TECH replied 7 months ago.

the only injector cleaner that really works is chevron Techron.

I know Costco sells it and so does the chevron gas stations.

knowing this isolated to the #4 cylinder I would first try the additive and also make sure to add this on a empty tank before fill up, make sure to use premium fuel so you get the cleaners in addition to the additive.