Hi i've been getting a CEL i've pulled the codes and this is what i get.

P0300 Random Misfire
P0301 No. 1 Cylinder Misfire
P0302 No. 2 Cylinder Misfire
P0303 No. 3 Cylinder Misfire
P0304 No. 4 Cylinder Misfire


A little history about the car its a 2005 with 51,000 miles on it. I am the second owner i bought it when it had 20K miles on it and it drove fine. at around 40K miles it started to idle a bit loud so i thought it needed a valve adjustment. Got one done and all seem normal then at 45K miles a started getting a CEL (It would sometimes flash as well).

I've tried the following to repair it.
New Plugs
Swapped with known working Coil packs
Swapped with known working Crank angle sensors
New MAF
Another valve adjustment


The car runs fine but the light really annoys me. I havent done any engine mods between the inital valve adjustment to when i got the CEL except a viper alarm system. Also sometimes the CEL will go away on its own but then come back.

Please Help

*** UPDATE ***
2-10-10

Did a leak down test here were the results

Cyl 1: 5%
Cyl 2: 35%
Cyl 3: 30%
Cyl 4: 45%


Weird things is the car still runs fine even idles great as well.
anyone have some insight into this?

 

cracked retainers

 

it's an ap2 so probably not cracked retainers?

i wouldn't doubt if all the injectors are clogged...of all the s2k injectors i've ever seen, the tips are always covered w/ gunk...

 

Do you get a slight pop from exhaust on idle?

 

the only other thing it could be woudl be a timing sensor issue coming from either a mechanical defect in the chain or a bad sensor telling the computer to fire too early.

 

What if does get a slight pop from exhast at idle???

 

Can you feel the misfire?
When you installed the spark plugs, did the car feel like its misfiring less or check engine light not come back on right away (maybe a few days later)?
How consistent is the misfire? all the time or randomly?

 

Read through this thread > Misfiring - Rough Idle - Codes for all Cylinders, 1/1/08 - UPDATE - still runs great!

It might help.

The pop is from RM.

 

slight pop from exhaust and random misfire turns out it injectors. It's the only symptom I had all the time when I had this issue, the cel we're random (sometimes 1000 km between cels).

I went thru this whole troubleshooting process not too long ago...

https://www.s2ki.com/forums/index.php?showt...&#entry15754631

 

it would prob come and go with the quality of gas you got... different places have different formulas