Misfire Issue 02 EX

SteveOramA

New Member
2002 EX w/1.7L Auto Trans

My CEL will light up for a few days and then shut off for a week or two before lighting up again. I got the following misfire codes about 2 months ago: p0302 p0303 p0304. I was told that cylinders 2, 3, & 4 were misfiring.

I replaced the plugs when this first started about 7K miles ago. I am used to working on older vehicles that have a normal looking distributor and plug wires etc.

Is there some troubleshooting I can do at home on my vehicle to help diagnose the cause? Please help me with a diagram or simple instructions. I hope this is a simple fix.

Thank you
 

2NRSTV

Team Exile/ADO Garage
Registered VIP
Check Compression in all 4 cylinders. Compare 2, 3, and 4 to 1.
 


RonJ

Banned
Two months ago you pulled misfire codes. You may now have different new codes. Pull the CEL codes right now and then clear the codes. Post all codes you find. Next, drive the car until the CEL turns on and pull the CEL codes again. You should only troubleshoot repeated codes.
 

gudoffer

New Member
5+ Year Member
spark plugs...was for me check them first...my cylinder misfired cause of em...
 


helofast

New Member
5+ Year Member
Wipe the codes and drive it a few days, if they come back up first things to check is your spark plugs and wires. Mine has done this before, I wipied the codes and they haven't came back again ever since.
 

SteveOramA

New Member
I failed to mention that the same codes in my original post have been read and reset several times. The same codes keep coming up when then the CEL is on, or have been pulled from the history after the CEL has gone off.

A compression check was completed on all 4 cylinders. They are reading the same and operating where they should be.

Should I look into replacing my ignition coils?
 

RonJ

Banned
What brand spark plugs did you install?

Cylinder 1 is the good one. Swap coil 1 and coil 2 to see if the misfire code follows coil 2. If not, then do the same swap test with fuel injector 1 and 2.
 

vjf915

New Member
Registered VIP
Registered OG
5+ Year Member
RonJ said:
What brand spark plugs did you install?

Cylinder 1 is the good one. Swap coil 1 and coil 2 to see if the misfire code follows coil 2. If not, then do the same swap test with fuel injector 1 and 2.
Click to expand...
Im pretty sure that if he swapped coil 1 with coil 2 then his ignition would not be in correct timing with his cylinder cycle. Do you mean switch the spark plugs?

Edit: Or do you mean to unplug the coil pack from the wires and switch them? Sorry, I think I misunderstood you.
 

RonJ

Banned
vjf915 said:
Im pretty sure that if he swapped coil 1 with coil 2 then his ignition would not be in correct timing with his cylinder cycle. Do you mean switch the spark plugs?

Edit: Or do you mean to unplug the coil pack from the wires and switch them? Sorry, I think I misunderstood you.
Click to expand...
As you mention, changing the firing order of connectors would be bad. No connectors will change position, only the coil packs or fuel injectors. The same test can also be done for plug 1 and plug 2, though I'm interested to know whether non-OEM spark plugs are currently installed.
 

vjf915

New Member
Registered VIP
Registered OG
5+ Year Member
That may be the problem then. Good call Ron, it was weird that he was throwing codes for 3 of the 4 cylinders.
 

lowlife9

New Member
Registered VIP
5+ Year Member
check the gap on the plug i believe it should be .044 . and definitely swap coil packs to see if one is bad.
 
You must log in or register to reply here.


Top