Code Help Please P0302
 

First off, I'm new to the forum and to the X5 so thanks in advance for your help. I've only had the thing for a couple of weeks and my first fix was the tailight prob. Today, I got a P0302 code and it was misfiring. I took it to Autozone and the code reader said

P0302- Cyclinder 2 misfire condition
Cause- Plugged or faulty fuel injector
Vacuum leak
Engine Mechanical Condition

I've done a search but couldn't find anything on this. The strange thing is, it was misfiring when I took it to autozone and when I left Autozone, it was running fine. The SES light was still on but all cylinders were firing. Any suggestions on where to start? Link me to the info and I'll get on it!

Thanks, Nat


Almost forgot. 05 4.4

check part #1 of this link:

RealOEM.com BMW E53 X5 4.4i Vacuum control - engine

you can possibly fix or replace. this in addition to a couple of vacuum lines on the top of the x and you should be up and running. buy some vac tube form autozone and replace the white and black and blue and black lines if they look worn or cracked.

how many miles? maybe need new plugs? a little injector cleaner?

It could be a number of things but first make sure you put premium unleaded 91 or 93 octane.

Check your plugs and see if they're fouled and need replacing.
Next, give it a good fuel injector cleaning, through the air intake and gas tank.

This is easy, narrows things down a bit and should help but, it could be more complex if it doesn't.

Let us know.

I'll check those things out. Its kinda complicated because I got this for the wife as a gift and her Bday isn't until friday. Would suck handing her the keys to a broke X5! :wow: So I really don't have a lot of time to troubleshoot and fix. I'm going to shoot home with it now and check the #2 plug. Its kinda strange though that It didn't misfire after I left autozone. All these electronics!!


Keep the suggestions rolling!

From OBD-CODES.com
 

P0302 Code - Cylinder #2 Misfire

Technical Description

Cylinder #2 Misfire Detected
What does that mean?

A P0302 code means that the the [COLOR=#009600! important][COLOR=#009600! important]car's [COLOR=#009600! important]computer[/COLOR][/COLOR][/COLOR] has detected that one of the [COLOR=#009600! important][COLOR=#009600! important]engine's[/COLOR][/COLOR] cylinders is not firing properly. In this case it's cylinder #2.
Symptoms

Symptoms may include:

• the engine may be harder to start
• the engine may stumble / stumble, and/or hesitate
• other symptoms may also be present

Causes

A code P0302 may mean that one or more of the following has happened:

• Faulty spark plug or wire
• Faulty coil (pack)
• Faulty [COLOR=#009600! important][COLOR=#009600! important]oxygen [COLOR=#009600! important]sensor[/COLOR][/COLOR][/COLOR](s)
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter(s)
• Running out of fuel
• Poor compression
• Defective computer

Possible Solutions

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the [COLOR=#009600! important][COLOR=#009600! important]car[/COLOR][/COLOR], it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, [COLOR=#009600! important][COLOR=#009600! important]distributor [COLOR=#009600! important]cap[/COLOR][/COLOR][/COLOR]
http://kona.kontera.com/javascript/l...rey_loader.gif
, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the [COLOR=#009600! important][COLOR=#009600! important]exhaust[/COLOR][/COLOR], your cat converter needs to be replaced. I've also heard in other cases the problems were faulty [COLOR=#009600! important][COLOR=#009600! important]fuel [COLOR=#009600! important]injectors[/COLOR][/COLOR][/COLOR].

Perfect thanks! It hasn't misfired since then and I give the car to the wifey tomorrow(as a Bday gift). As a precaution, on Saturday, I will change all the spark plugs with the NGK IR and will change the #2 coil pack as well. Hope this takes care of it! :thumbup:

On the topic of the NGK IR plugs
 

I run them now. I swapped them out about 3K miles ago and notice no real difference in day to day driving. I think up top at higher RPMs, they pull a little stronger based on the butt dyno. The plugs I pulled out were the BOSCH BMW plugs which look like the BOSCH +4 Platinums.

Do NOT try to gap them or check that the gap is accurate!!!

I know that may sound stupid but I just wanted to check that the gap was correct @ 0.032 and I ended up snapping the tip off the electrode. But there was significant force involved in using the AutoZone-round-keyring-gap-checker-thingy.

:bustingup Sorry for your woes, but point taken! Won't mess with the gap! :thumbup: