P0302 code

[06 H3]

My brother came home from school and wanted me to play this song in the 3 because he loves my bass compared to his. I start it up listened to some song then I look down and a code came up. P0302. cylinder 2 misfire! Damnit....funny because my brother drove my car earlier today...damnit nick....how much of a bitch is this gonna be to fix.

 

[3Hummers]

Could be a number of things, some not so expensive, some a little closer to wallet draining status.

 

[Bigunit]

Found this on the interweb:

A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically why it's mis-firing.

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 P0300 may mean that one or more of the following has happened:
Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
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 car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, 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 exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors or a bad head.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

 

[erdlen65]

did anything come up on your dash (ie. Reduced power mode, traction control, stab system failure?

 

[06 H3]

Thanks Big unit. I have 79k miles on an 06. I guess I will stop by the dealer tomorrow after class. Lately it has been tougher to start but that was electrical...I ordered tsunami battery terminals. The idle has been a bit rough and I recently had the TB cleaned.

The engine bay has been covered in mud for a while, could this be an issue with getting dirt and crud inside the motor?

I am trying to decide if I should just clear it and see if it comes back or take it in

 

[06 H3]

did anything come up on your dash (ie. Reduced power mode, traction control, stab system failure?

Nope, not in park. I will go drive it around though.

 

[Bigunit]

The mud and crud in the engine bay may be causing the issue. At the right front of the engine cylinder head behind the upper timing cover is located the camshaft position actuator This actuator solenoid controls engine oil flow to the camphaser. When this solenoid plugs up the cam angle information is not correct and hence the misfire code. You can remove it and clean the passage itself or use a oil engine flush system prior to oil change. From what I have read, camshaft solenoids are a coomon cause or another common cause is a bad or faulty coil pack.

 

[f5moab]

A P0302 can be more of a problem than the random misfire P0300 code. The random code is just that, the PCM cannot identify which cylinder is the problem, whereas the 302 code has pinpointed the problem to number 2 cylinder.

First step is to clear the code...
Then see if it comes back. If yes, keep going, if not, it could just be a brain fart.

Since this is specific, usually not fuel type related (meaning the station where purchased...bad fuel is usually not specific to a cylinder but is random). But could be a faulty or dirty injector, so Techron might clean the injector to keep the code from returning.

If it comes back...
Switch the coils between 2 and 3, clear the code and see if it come back as 303 or remains as 302. If it is 303, coil is the problem, if comes back as 302, keep digging into cylinder 2.

If high miles, might be good to change plugs. I only recommend factory specific plugs, but probably a good Bosch or other would be ok.

Then clear and see if it comes back.

Other items that can cause a specific misfire code:
A misfire may only occur when the engine is under a load or when the engine is cold

A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the following possible sources:
A tire or wheel that is out of round or out of balance
Variable thickness in brake rotors
Unbalanced drive shaft
Rough road conditions
Damaged accessory drive component or bad belt
Damage reluctor wheel
Cylinder head or other internal head components such as guides, valves, etc.
Although, I would say if it is sudden then most likely injector or electrical

 

[f5moab]

The mud and crud in the engine bay may be causing the issue. At the right front of the engine cylinder head behind the upper timing cover is located the camshaft position actuator This actuator solenoid controls engine oil flow to the camphaser. When this solenoid plugs up the cam angle information is not correct and hence the misfire code. You can remove it and clean the passage itself or use a oil engine flush system prior to oil change. From what I have read, camshaft solenoids are a coomon cause or another common cause is a bad or faulty coil pack.

If the actuator plugs, it should be a random code, not cylinder specific. Won't say it will never happen, but chances are it will affect all or be random.

Injector, coil pack and plug are the most common (early 06 vehicles) in producing a cylinder specific misfire code. After that comes internal cylinder head components....

 

[06 H3]

I believe the plugs have never been changed. I havent and the dealer probably has not either. I will try that seeing I am at 79k. Also excessive vibration...This may sound ridiculous but I have an aftermarket headunit with a bass booster and the song was bass boosted too. Could the vibration cause a cyl 2 misfire? I know it sounds crazy but that is when I saw it...Just trying to think of every possible issue

 

[alrock]

Who knows? Clear the code and see if it comes back as F5 suggested. Also, if you haven't taken off the intake and looked by your plugs and coil packs it might be good to see what kind of mud you have in there if you've been romping.

 

[f5moab]

Yes, a heavy vibration can set off a misfire. Not a usual occurance, but it has happened (hammer on the engine block can do it almost everytime. And if you hit just as number two was being monitored, it could, but you would really need a hell of a lot of power and the bass is in the rear. But I'm betting on plug or coil. So, before replacing plugs, switch the coils and see if the code goes with the coil or remains with the cylinder. If remains, then do a plug job. If that does not cure it, it is time to really get serious.

 

[06 H3]

Ok guys, I just got out from working on the hummer. I cleared the code and the plugs look clean and everything internal looks clean....WOO no mud! The plug has probably seen better days...I pulled it and I will probably have to replace em. For now I just put it back and no codes have come back since.

 

[erdlen65]

Some 06 H3s have faulty pcms take it to a GOOD dealer and have them run the numbers on yours if it falls under the list of serial numbers they will replace it, but that I think is only covered under emitions warrenty that runs out at 80k so if your close I would have it checked before you gotta pay

 

[06 H3]

I will call them and see if mine is under that. I am just under 80 so I better hurry lol. I cleared the code and nothing has come back yet

 

[06 H3]

UPDATE: I cleared the code and it hasnt been on since. The plugs should be changed soon but I have also seen plugs much worse. I think it was a brain fart or vibration that threw the code. Happy Hummer= Happy Me

 

[3Hummers]

Cool

 

[Dennis]

This looks like as good as place as any to post about My head Problem..No not that one, the the one in the H3:giggle:



First of all, I have an 06 H3 with 53K miles and the VIN is in the range of the faulty heads that everybody was having problems with being bad valves (soft seats) a few years ago..I knew it was going to show up sooner or later, so that's one reason I bought an extended warranty...:thumbs:


A couple of weeks ago the CEL came on and it coded out as P0304 (misfire cylinder #4)..I went the easy way first and replaced all the plugs and swapped coil packs with another cylinder..[BTW I bought those high dollar, 1 million watt PULSTAR Iridium Plugs (#EF1i)]..I cleared the code and drove for about two weeks and the damn CEL came back on..Idle was smooth and power was good or normal...Checked code again and it was the same; P0304...Took it to the dealer and after some testing they advised me I needed a new HEAD..old one had leaking intake valve seats, especially #4 cylinder....:shame:


Anyways...I got my baby back today and all is well:woot:..they did a real good job and nothing looking left undone..clean and neat under the hood..With it came; a fresh oil change w/filter all new coolant..Being an ANAL AZZ, I asked what kind of oil? They said their usual Mobil 10w30 dino oil..Okay, I appreciate what they did, in fact is was a good idea..So as soon as I got home I changed the oil back to my brand that I've used since the truck was new (Castrol synthetic Edge 5w30) w/new filter..At least any metal or dirt left over, is well flushed out now..The work order did say they had to drill out two head bolts because they snapped off while removing the old head.

I also learned they wiped out my PCM tune that I got years ago from PCM for Less..I loved that tune..So now I need to get in touch with them again and see if thay can re-tune my PCM again..Wasn't a retunes free if the dealer dumped it?..I seem to recall that..Anyways..Does anyone remember the girl's name that run the show at PCM for Less? Was it Marie or Mary?..I remember Alvin was the man doing the Tunes..


Thanks for viewing..I know I like to run off at the fingers..

 

[alrock]

Kelly is the contact at pcmforless.com. They are a forum sponsor. Don't recall any of the details of their deals.

 

[Dennis]

Kelly is the contact at pcmforless.com. They are a forum sponsor. Don't recall any of the details of their deals.

That's right..'Kelly'...Thanks alrock..I guess I should also mention I'm part of the H4O klan now when I call..

 

[Dennis]

Talked to Kelly today at PCMforless..and they will re-tune my PCM with the latest version, for free..I only pay for the two way shipping..which is very fair.

They are a great company to have as a sponser here.

 

[Dennis]

Update:

Received the LOANER PCM for my H3..Installed it and had to go through the Security relearn process, otherwise no other issues (takes about 35 minutes of turning the key on and off)..anywho..sent mine off to 'PCM for Less' to get the latest tune version..

Let you know how it turns out when I get mine back...They promised marked improvement from when I first got the original tune back in 2006.

 

[06 H3]

how much does this normally cost to have a new head installed? I keep pulling the P0302 after spark plug and coil pack change...I have heard you can get some money back from GM if you argue with the people at hummer customer service

 

[Dennis]

how much does this normally cost to have a new head installed? I keep pulling the P0302 after spark plug and coil pack change...I have heard you can get some money back from GM if you argue with the people at hummer customer service

Having just had my Head replaced..Total charge was $2700.00...Head itself was $811.00...Labor rates may vary depending on locale.

 

[06 H3]

o jesus! my I5 just became a I4...LOL. This is gonna fricken kill me but gotta keep squeaky squeakin'