Engine miss-fire

[kershope]

Hi I have a 2001Civic 1.6 SE - misses at low speeds - 20-50mph/approx 2500rpm - ok at 60mph and above it never misses a beat - goes for a while with the miss but engine light doesn't come on then goes through a phase of missing badly and puts the engine light on (P codes for all cylinders + multi-cylinder miss-fire)
Have changed the plugs and renewed all 4 individual coil packs on each plug - any suggestions welcome

 

[Wreckless Hype]

Welcome to the site.

Have the injectors ever been serviced or removed / disconnected? For it to be all cylinders, you likely have a fuel issue or a spark issue. If the injectors were mixed up, I would imagine that would through things off. If something like your FPR or fuel filter may be messed up. You may not be getting consistent spark. It's hard to say, there could be a few different things causing this.

 

[joe7987]

Any there any sort of diagnostics he might be able to try in order to get a better idea?

 

[Wreckless Hype]

I'd say start with a full tune up, you've already changed the plugs - were they the plugs specified in the manual, as OEM by Honda? I'm not sure exactly what "renewing" the coil packs entails, could you explain that? Change the fuel filter and air filter also. Check all of your major ground points.

How many miles are on the car?
Can you check the fuel pressure?
Timing?
Possibly a compression test?