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Hello,
im having problems with my civic its an 02 ex 1.7 liter its throwing off the codes p0300 p0301 and p0302, which are misfire codes for cylinders, i have changed the coils and plugs and oil, no change, everyone is saying that i need to clean the air intake control valve and the MAF sensor? where are these located under my hood? please help the car's idle is low and kinda shakey. the car has hesitation when accellerating. whats next?

 
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I would suggest purchasing a manual. The shop manual is like $60 from helms, or just grab the $15 one from your local parts store.

I think most of what you are asking for can be found here:
https://www.civicforums.com/forums/1...e-up-mods.html

I'm partial to the EGR valve, but that is my personal experience when my engine was misfiring. Capture the freeze frame data, if you can, reset ECU, unplug EGR and see if problem can be replicated.

 
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Ok so i finished everything on the list but the air canister filter and the o2 sensor and the codes disappeared.... now Im throwing off a p0113 something about IAT sensor ?? any clues in what direction i need to go?

 
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ok, so back to square one, my dumb self forgot to even plug in the IAC sensor... now im throwing off the codes again and i still have hesitation.... im thinking fuel pump or filters

 
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What codes do you have now?

Clear all the codes (remove your negative terminal for a few minutes) then plug it back.

Drive it around and see what codes come back now. Post back with that info.

 
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p0300 p0301 and p0302
which are random cylinder misfire
cylinder 1 misfire
and cylinder 2 misfire...
i talked to a mechanic and they said that it would be caused by lack of fuel pressure?
so im guessing that the fuel strainer and filter in the fuel pump are clogged to ****? what do you think

Thanks,
Ben

 
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Sure, it could be a lack of fuel pressure. It could be spark plugs(bad/wrong plugs or improper gap). It could be a vacuum leak. It could be low compression(and what ever is causing that.) It could be fuel injectors or the associated wiring/control unit. Could be low fuel pressure due to several issues. Or I could *guess* several other things.

Did you check the fuel pressure? If it is out of spec, helms manual says to replace fuel pressure regulator AND fuel filter. Then recheck fuel pressure. Could be a valve adjustment is in order. Could be the EGR valve. Could be the VTEC. You could just replace piece by piece until it goes away or do some troubleshooting.

I'd suggest stop guessing and provide some more information and some more thought. When does the fault occur? Idle? Low rpm under load. Acceleration?

Reset as 04 Honda Civic and attempt to replicate the problem. Also note when it happens. Stop at a stop light? Accelerating? Can you read freeze frame data.

 
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Yea freeze frame data would be ideal, many scanners can do it. Even some of the cheaper scanners. Not sure if the one autozone sells does.

 
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Whew... alright guys... i guess im in for alot of work... thanks ill research it out from here

 
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Hopefully it's not a lot of work and something easy. Replacing a fuel filter and/or other components in that area sounds like a lot of work.

If you provide more info, I think people will be better able to help you. And make it easier

 
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Does anyone know the fuel pressure spec?

 
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and how i go about checking this pressure??

 
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Here you go...

 
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Alright guys, whats next
I checked the compression and its around 210 on cylinders 1,3,4 and around 70 on cylinder 2? i pressurized the cylinder at TDC to try and see what is leaking but there is no telling really, kinda sounds like small bubbling through the oil cap hole... but i dont know, what do you say i start with??

 
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So, put some air on the cylinder at TDC and check a few places. Do this in as quiet of an area as possible. Stick your head in the engine bay and just listen. Then try some of these:

- Listen at the oil fill hole.
- Take the air cleaner off and listen at the throttle body.
- Listen at the tail pipe.
- Check radiator for bubbles.

That air is going somewhere.

 
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Have you been going through any coolant? A blown HG has been known to cause misfires in these cars. 70psi is pretty low...

 
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Hello again,
finally got back from AK and tore this thing apart. ended up with one badly bent valve that didnt seal and i actually had all 8 exhaust valves bent. had it rebuilt for $320. but im worrying about putting it back together. if it bent all eight it must have skipped a tooth or has a malfunctioning vtec solenoid right? HELP its a 1.7 vtec by the way. if any expert wants to give me a call and help me out feel free my home number is 936-851-0105 ask for Ben. Thanks

 
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So as I am putting this thing back together i realize that the bent valves were intake valves....

 
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So im still working on this damn car... i have everything back together and im still getting random misfire misfire cyl2 and cyl4 codes.... any other ideas?