Thread: P301 Code - P11

Hey guys, here's the deal. My gf's P11 is throwing a P301 code - which is a cylinder #1 misfire code. Here is a preface to this:

About a month ago, her car threw a knock sensor code and a multiple cylinder misfire code. I changed the knock sensor, cleared the codes, and within a minute, threw another code.

Now here i am, with a cylinder #1 misfire code. The car has brand new plugs, and recent wires, cap and rotor.

The only thing i can think of is a fuel injector, or a few injectors.

What do you guys think? The car DOES has 205K........

Let me check the FSM I have for that code and see what can cause it. I will post tonight. I am having a hell of a time with a code myself that causes my car not to idle!!!! it is the infamous MAF code --- P0100 MAF Sensor !

got this off the web dave, maybe it will help..

A code P0301 may mean that one or more of the following has happened:

Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

the thing is that if he had a bad coil, he would get p0300, p0302, p0303 & p0304 usually. said tune up stuff was ok. i would check into that injector and also look at the itm gasket and make sure it doesn't leak at the #1 runner. do you have a scan tool with realtime?

I don't.

Personally, i think it's the injector myself. The car has a little skip to it, below 2500RPM's.

Thanks for the help guys.

Dave- btw, that p0300 code comes up before it notices which cylinder is missfiring or if it is really random. if a p0301 came up after, which it did then you don't have to worry about that p0300 that is in there, many times they will both be in there.

Well, after i cleared it, the p0300 went away, and the p0301 appeared, so yeah what you're saying is right

injector clogged. leaning out cylinder # 1

FSM says it could be any of the following:

Improper spark
Low compression
low fuel pressure
EGR valve stuck
Injector circuit shorted or open
bad injector
lack of fuel
drive plate or flywheel
incorrect dist. rotor

Brent

Make sure you dont have a vacuum leak at the #1 cylinder ... Intake gasket or ?? Also I have seen EGR systems get plugged so 3 of the cylinders get no EGR and one gets it all... causing a misfire code ...

yea, Injectors are common ..

Another far out issue could be the flywheel or flexplate ...I have seen where the teeth get chewed from the starter and cause P030x codes , usually you get starter grinding though ...