Searched, and can't find a somewhat certain answer...

Replaced:
-Rear valve cover and seal - 6th gen
-All spark plugs - OEM
-MAF - AM600
-All coilpacks
-PCV Valve

-ECM Updated to latest software (Cleared O2 codes)

Anyone have any insights for me?

 

Anyone? Bump?

 

Injectors?

 

what is the air fuel reading?
Next thing to check is injectors.
If you run too lean 25% or more you will throw random misfire as well along with lean running condition perhaps. (vacum leak)
Did you replace IM gasket?
DO you get a missfire cylinder nr? If you do swap injectors and see if it follows it.
Also a clogged cat could cause it (less likely)

 

COIL PACK?

 

My issue was the whole engine harness was fried they replaced it and one of the connections for the cylinders might be loose.

 

mine went away when I swapped my ssac headers to cattman headers, i had a nasty exhaust leak, and one of my o2 sensor wires had become disconnected.. dunno if it was one or the other but the car has been running so smooth ever since and no more P0300.

 

crank sensor.

 

it will give you a code for crank sensor if it skips reading on crank and also if resistence is not within spec

 

bringin back this old thread. i have pm'd zero about this. i get p0300 random missfire code a lot lately. dono wat it can be. i have new plugs and manifold spacers. theres no leak or anything. looks like ima have to check the injectors. crank sensor really? hmmm

i got a feeling it might be injectors. the car doesnt seem to miss.. maybe once in awhile itll backfire. for the most part its not doing it. this damn ethanol in the fuel might be slowly killing the injectors. im leaning toward maf or injectors.. this sucks dude. if ima do injectors i may as well swap for beefier valve gaskets..

 

aight so I have a 00 max and it started shuttering about 3 weeks ago. Since then i have replaced spark plugs, coil pack, 02 sensor (bank 1, sensor 1), I have good air flow out of the exhaust, and I cleaned the MAF. Now all I am getting as far as codes is random misfire (p0300) and bad MAP sensor. I know the MAP has something to do with air/gas so could this be the problem, it cost like $142 so I just want to be sure before I go to spending even more money, because I thought all the "listed above" would fix it. So what do ya'll think?

 

i'd say that you ave a small vacuum leak. everyone seems to overlook the fact that our manifold gaskets can become brittle and cause tiny leaks. any air getting into the engine after the maf will cause a lean code. when you replaced the plugs did you replace the gaskets? was the rubber soft or brittle?

 

I didn't remove the manifold when I replaced the plugs on bank 1 (closest to firewall), so no I didn't replace them and don't know if they are brittle or soft. Wouldn't I here a suction noise if there was a vacuum leak? If so what sound would I listen for?

 

oh yeah my car has 133k miles on it. How hard is it to replace the gasket and approx. how much will it cost?

 

if it's a pinhole leak I doubt you would here it. check with Dave B for prices, or courtesy nissan has a website as well. there are 3 gaskets which could be suspect

 

would holding a lit cigarette or something with smoke possibly show it sucking air or would that not work?

 

Diag. test done on sat. found a bad connection to a fuel injector.