P0300 misfire and P0449 EVAP System

[jakesz28]

Well this code has been on for a while I have about 60,000 miles on it now. Do I take it to the shop or try to fix it myself. I have lost MPG since the codes have been on but the temps are a lot colder too. So I found a pic of what I think the evap solenoid is. I guess the first thing of look for vacuum leaks.

2007 3.7L

 

[f5moab]

I suggest clearing the codes and seeing if they reset. Fuel mileage naturally drops in colder weather.

The 0449 code is for the vent solenoid, located at the evap canister by the fuel tank. You might want to check with your local dealer. The EVAP system is covered for extended miles in many states since it is an emission requirement and some states took it a bit further than the feds and required a longer warranty on emission items. Not sure of IA laws; so best contact the dealer to find out.

 

[algin5109]

You have any problems filling tank with gas

 

[jakesz28]

Nope the tank fills just fine. Put the nozzle in and set it, does stop till its full.

I have reset the codes and the P0449 comes up right away. The P0300 takes longer to come back.

 

[jakesz28]

I know the bumper to bumper is over. I also believe the other warranty is up. I'm not sure about the extended emissions warranty. I tied getting the radiator warrantied right after the bumper to bumper was up and was denied. They wanted $1000 and I was able to repair it for $200. So I'm afraid of of what they will want for this.

 

[f5moab]

I wanted to add earlier but forgot. I HAVE NO idea what year vehicle or engine you have. When anyone starts a post asking for help on a particular problem it is a great idea to post the year of the vehicle, type and engine/trans. You say your bumper to bumper is up, but what about your powertrain? See, I don't know if you have a 100K powertrain or not.

 

[jakesz28]

Yep I should have known to include that. Its a 2007 with the 3.7L engine. Auto trans.

I don't remember the exact info on the power train warranty but it only lasted a couple months longer then the bumper to bumper. I wish the power train was 100,000 but I don't think it is.

EDIT. I was looking at the paper work from buying it. Can't find anything about a warranty other then 3 months and 3000 miles, from the dealer. I will have see if in still covered on the 5 year part of the original warranty.

 

[ArtHummer]

Not sure how it is on Hummers, but on some cars this code comes up when you feeling the gas wile engine is running. Clear the code first and see if it will come back on.

 

[jakesz28]

Yep cleared the code. It was back in less then 5 miles of driving. My wife just went to the dealer. The warranty is up. They wanted $100 just to scan the codes. So I told her to forget it. Looks like I need the part number for the purge solenoid and vent solenoid. If I'm not mistaken there are two solenoids in that circuit. I'm going to replace both of them.

 

[jakesz28]

Does anyone know for sure if the canistaer purge is 214-1680 ac delco and the canister vent valve is 214-2241 ac delco. Or do you have the GM parts number so I can go thru GMparts direct?


Thanks for the help

I had to call a different dealer to get GM part numbers. I think they are
canister purge solenoid 12597567
canister vent soleniod 20907779 (which comes with the hose)

 

[alrock]

Gene at GMpartshouse.com is always helpful in getting you the right parts. Good luck with the repair.

BTW, if you have an Android phone I recommend getting this http://www.ebay.com/itm/ELM-327-V1-..._Automotive_Tools&hash=item51a67c3c47&vxp=mtr and the Torque Pro app. You can then read the basic codes (and a lot of performance data) without going to a dealer.

 

[jakesz28]

I actually have HP tuners pro and can read all codes and do some of the relearn stuff that you usually have to go to the dealer for. Currently I just scanned it with a cheap hand held computer. I guess I should take the laptop out and see what tests this scanner on the laptop can do to the evap system.

 

[Happy Hummer]

[h=2]P0300 misfire and P0449 EVAP System[/h]The p0449 is exactly what my GF's H3 (2006) has going on at the moment. Spent a bunch of time to research a less expensive alternative to this expensive small evap part. Here are some of the cross reference #'s:

https://sites.google.com/site/happyhummer01/p0449-resources

By the way, the vent valve resides where f5 showed ya. The other purge valve is located on the engine nearest the drivers side. This is usually indicative of the code 455.
2 different codes and parts.

In order to use the ac del part in the reference all have to do is get a short piece of hose and hose clamps. Make sure it is rated for gasoline.

Chris

 

[f5moab]

Not sure why you are replacing both solenoids since the code directs you to the vent solenoid. Usually, the computer is pretty precise on the solenoid that has failed or the circuit(s). The evap control solenoid could last another 50K miles (or yes, it could fail in a week). Guess I'm the type who usually replaces only those items that fail, so long as it is not an access problem.

 

[jakesz28]

Well looking on the web on another Hummer forum someone else posted that to fix the P0449 he had to replace the purge valve on the side of the block. I can't say he was right or wrong. But if I order the vent valve from GM parts direct its about half the price that the dealer wants. The purge valve is only $23 so I figured why not? Thanks for the help. Maybe I will spend the $23 and save it just incase? The shipping will be about the same for or both parts.

 

[Bigunit]

Let us know if it solves your issues. I hope it does.:thumbup:

Sent from my DROID RAZR using Tapataint

 

[jakesz28]

I got my parts today from gmparts direct. I will replace to one by the gas tank first and hope that gets rid of the one problem. I'm afraid the misfire code is caused by something else. Hopefully I get it on this week end.

 

[alrock]

Good luck

 

[jakesz28]

Today I finally replaced the vent valve. It was bad with out a doubt. It looked like it over heated and started to melt and cracked the housing. When I cleared the codes this time all I had was the P0449. So I cleared it and no codes on the way home. I have to thank you guys and Brian also for letting me use his garage.

But one more part you have to add on the bill is GM changed the electrical plug. I did not have time to wait to order that so it was full retail at the stealership. $40 with tax. Part number 19257603.

 

[jakesz28]

Well today I got the P0300 and a P0442. So last time I had a P0449 and changed the vent valve. Is this going to be the purge valve this time?

 

[Xlr8n]

Well today I got the P0300 and a P0442. So last time I had a P0449 and changed the vent valve. Is this going to be the purge valve this time?

P0442 is evap system leak detected. Check hoses and fittings. You likely have a leak from when you replaced the vent valve.

The P0300 is a random misfire code. Causes could include: Cheap grade fuel, clogged cat, intake leak, or dirty TB and/or MAF sensor. There is an outside chance your leak in the evap system may trigger that code as well. I'd find your leak and go from there.

Do you mind me asking what you paid for the new evap vent valve?

 

[4speedfunk]

Try a new gas cap.

 

[jakesz28]

I think the vent valve is $190 at the dealer but I went thru GM parts direct and got the vent and purge valve for around $160. I would have to try and dig up the receipt to know for sure.

The code has been off for a while I have a hard time thinking that the leak is at the fittings I disconnected but you never know. I would have thought this would of came back quicker if it was. I replaced the vent valve as an assembly with the new hose and not just the valve.

I will check on that gas cap.