P0449 and P0455

[J Wikoff]

I had P0449 pop up after filling the gas tank the other day. P0455 was pending. I tried reseating the gas cap to no avail. Hoping that I didn't have to drop the fuel tank and replace an evap canister or something like that, I ordered the newest iteration of the gas cap from Amazon, $20 or so. I kept clearing it over the next couple days, P0449 was always active with P0455 pending. Got the new cap on yesterday. After 4 or so drives the CEL has not come back on, so I think I finally fell victim to the wonky stock gas cap after nearly 70k miles.

[J Wikoff]

Well, fuck and a half. I spoke too soon. Codes came back today. In fact, I can clear them, key on/engine off, and they come back several seconds later. The engine isn't even running. Now what? I swear this car is the worst. I haven't had a whole lot of cars, but this one needs a relatively lot of damn hand holding. There's always something to fix. I finally think I have my water leaks fixed, and whammo, check engine light.

[TonyKarter]

I have them too. For so long I forgot them. Clearing "check engine" prompt happens subconsciously now, without thinking. Come on, admit it. You know you want to drop that tank, don't you?

Gonna' make it a positive and use it to motivate me to install that fuel pump I may need one day.

[J Wikoff]

This no remote start because of the CEL is ticking me off.

[J Wikoff]

What should I need to replace the purge valve? Are there any bolts that are likely to break? Any install tips? I might have a chance to replace it next weekend.

[WhatNext]

Saw multiple posts where the valve (and canister?) were able to be changed from the wheel well. Not easy but sounds better than messing with the rear cradle and gas tank.

For those not familiar, a dealer charged me $850 to do this job.

[LDM]

What should I need to replace the purge valve? Are there any bolts that are likely to break? Any install tips? I might have a chance to replace it next weekend.

The purge valve or the vent valve? The purge valve is easy, it's under the hood clipped to the cylinder head. The vent valve, which is what throws P0449, is the hard one that's back under the car. This thread has a couple of tips: http://forum.grrrr8.net/showthread.php?t=18849 When I did mine, I dropped out the right rear exhaust section (I have a Corsa so this wasn't that difficult) and was able to reach in from above the differential. Doing it this way I was able to do it without lowering the cradle at all. The whole thing was a major pain in the ass and very frustrating, but if you have some patience it is possible.

[todds87ss]

What should I need to replace the purge valve? Are there any bolts that are likely to break? Any install tips? I might have a chance to replace it next weekend.
The cradle bolts are a PITA if you choose to lower it. I removed the drivers side and loosened the passenger side. They are loc-tited in. Go slow or whatever method you choose. The valve itself is clipped into the pan under the trunk. You will have to work it to get it out. Mine failed shortly after I overfilled the fuel tank due to a bad fuel nozzle failed to auto shut off. The P0449 code is a bad valve, not bad pressure, so it needs to be replaced. Don't worry so much about getting it out - break it if you have to. You just need enough of it to ensure you get the right replacement. And do not worry about the canister. It will dry out and be just fine. Take a look at the thread referenced below.
Good luck.


The purge valve or the vent valve? The purge valve is easy, it's under the hood clipped to the cylinder head. The vent valve, which is what throws P0449, is the hard one that's back under the car. This thread has a couple of tips: http://forum.grrrr8.net/showthread.php?t=18849 When I did mine, I dropped out the right rear exhaust section (I have a Corsa so this wasn't that difficult) and was able to reach in from above the differential. Doing it this way I was able to do it without lowering the cradle at all. The whole thing was a major pain in the ass and very frustrating, but if you have some patience it is possible.

[J Wikoff]

Yeah, I meant the one by the gas tank. Thanks guys!

[Napalm]

uhm before getting too far down the road.

did you check your gas cap and have you considered replacing it. I had purge codes along with something else. And for 8 dollar I tried it in an effort to save major pain.

new Stant Gas Cap (I could get it easier than an Gm part) and bickety Bam - no more lights. and that was 2 years ago.

[J Wikoff]

Yep, new cap. It didn't change the behavior.

[Napalm]

Yep, new cap. It didn't change the behavior.

sorry then. Good luck with the tank drop

[J Wikoff]

Before I tackle this, is it possible to relocate the thing? Should I need to do this again, I'd rather it be simple.

[todds87ss]

sorry then. Good luck with the tank drop


There is no need to drop the tank...this is a common misconception (similar to "the canister and valve are one piece")


Before I tackle this, is it possible to relocate the thing? Should I need to do this again, I'd rather it be simple.

you may be able to...you'd have to lengthen the wires. Look at the 04-06 GTO valve for reference. it's in a much easier place (fender well). Not sure it's worth the effort. after replacement, mine went another 80K (till I sold it).

[Cooper]

I replaced mine without dropping the tank. Dropped rear cradle which is easy and went in from wheel well. Whole process was less then an hour.

[J Wikoff]

Is dropping the tank all that hard relative to the cradle?

[TooManyHobbies]

Is dropping the tank all that hard relative to the cradle?

Dropping the tank instructions:

Step 1 - remove the rear cradle :D

[Pontiac88]

you may be able to...you'd have to lengthen the wires. Look at the 04-06 GTO valve for reference. it's in a much easier place (fender well). Not sure it's worth the effort. after replacement, mine went another 80K (till I sold it).

I think there is a write up with a few pictures showing how to get to this through the rear wheel well, passenger side if I remember correctly. It might be on the other G8 forum.

However I can't say much about it, a revised gas cap from the dealer did the trick for me

[Napalm]

AH

question then - if in the area and with cradle dropped - would you not also take the time to drop the tank - and replace the fuel filter?

[-Ray-]

Fuel filter is in the fuel pump. Cut a hole under the back seat.

[todds87ss]

AH

question then - if in the area and with cradle dropped - would you not also take the time to drop the tank - and replace the fuel filter?

I suppose if it needed to be done...That's like my wife saying "since we are replacing the stove, we should re-tile the kitchen :)

[Napalm]

I suppose if it needed to be done...That's like my wife saying "since we are replacing the stove, we should re-tile the kitchen :)

well I wouldn't go quite that far.

just figured if you have some miles on there (im at 139K right now) it might be a good idea to clean that out so you're not back there again in the next 20.

[J Wikoff]

I need help. I thought I knew where the thing is. I found something kinda similar on the passenger side to the canister that others have posted and have pictured in my hand, but the one on the car is smaller in diameter and has two lines attached to it. This replacement has just one port for a line. Where is this thing?

[J Wikoff]

Well, I figured out how to make the code go away without replacing anything. I read that an open circuit in the valve will set the code right away. So, I shorted the connector. I only clears the code and checked it again, and it didn't come back right away like it was. How long do you think I could drive like this without another code popping up?

[J Wikoff]

Well I didn't want to fry anything, like my car, so I just plugged it back in. Would it be cheaper to have a dealer replace the canister if I provide the right part, or by a tuner that can disable the code?

And if I get a tuner that can disable it like an HPTuner, and didn't want to try doing my own custom tune, could I disable the code, then use my existing SC Cortex over the top of that?

[Napalm]

Well, I figured out how to make the code go away without replacing anything. I read that an open circuit in the valve will set the code right away. So, I shorted the connector. I only clears the code and checked it again, and it didn't come back right away like it was. How long do you think I could drive like this without another code popping up?

so had I not fixed mine very easily with a new gas cap I too would have tried something like that a few years ago.

Nothing really wrong with it just you will vent some fuel vapors. Which is evil just like the PCV system. If you can keep the light off the car should be just fine without it.

evidenced by the fact that you can drive the car just fine for ever with the code lit in the system - you just can't use remote start. and that light gets annoying.


As far as what you did - nothing wrong with that perse but I would do a few things.

Option 1 - get the corresponding plug type that is the female version - - jumper the pins together - use that seal plug in place - coat/cover all wiring for wet/dirty conditions. IE like how the car was built.

Option 2 - make your jumper again but this time coat the wire - then shrink wrap it if you can or use quality electrical tape and secure the harness up and out of the way such that it won' tfall into moving parts etc.


In theory though nothing wrong with your idea. I do think however you would end up needing a resisor in that line, I don't know if it is purely an , on or off - situation.

[J Wikoff]

I measured and there was battery voltage across the pins, so I didn't want the paperclip getting hot and melting something, particularly near fuel vapor lines.

I have stuff for heat shrink. I found the later 09 valve and ordered it. If for some reason I can't get it installed, I'll rig up a bypass.

[Bob the Noob]

I had this pop up recently. Made sure I ordered the 09 part and had my local shop install it for 100 bucks. They looked at the normal procedure about dropping the whole cradle and all that, then said "Hell no we're not doing it that way." Dropped the passenger side down a bit and were able to reach it that way.

Good to know there's shops out there than work smart and don't over-bill the customers. :)

[MIEngineer]

I had this pop up recently. Made sure I ordered the 09 part and had my local shop install it for 100 bucks. They looked at the normal procedure about dropping the whole cradle and all that, then said "Hell no we're not doing it that way." Dropped the passenger side down a bit and were able to reach it that way.

Good to know there's shops out there than work smart and don't over-bill the customers. :)

Bob, I have a feeling mine is the same way. I am ordering a cap, but a new valve might be in order. Which p/n did you go with? I'll have to check mine.

Fun times.

[TonyKarter]

Waiting on a new GM cap to be delivered. Hope that fixes mine, but my luck usually does not run that way.

[Bob the Noob]

Bob, I have a feeling mine is the same way. I am ordering a cap, but a new valve might be in order. Which p/n did you go with? I'll have to check mine.

Fun times.

ACDelco 214-2164... which Amazon, if you have it set up with various cars, will say won't fit your G8 because it's not the entire assembly. I found the full assembly and it said that would fit, but I didn't need the canister so I didn't pay the 140 for it and ordered the $13 valve. :)

[Napalm]

ACDelco 214-2164... which Amazon, if you have it set up with various cars, will say won't fit your G8 because it's not the entire assembly. I found the full assembly and it said that would fit, but I didn't need the canister so I didn't pay the 140 for it and ordered the $13 valve. :)

that's beautiful - unless your canister has a crack - but you know they make epoxy for such issues.

[J Wikoff]

I finally got back in yesterday and got it all fixed. I dropped the cradle by removing all 4 bolts and the rear exhaust hangers. I did struggle for a few minutes trying to remove the outboard line from the valve. Then I remembered I had a set of those cheap fuel line disconnect collar tools. Dug those out and had the line off almost immediately. To those planning this job, get a set. You'll be happy you did. After installing the new valve, I cleared the codes to confirm that it did indeed fix the problem. Then I put in a set of BMR cradle bushing inserts and put the rest back together.

I did smoke my torque wrench on the third cradle bolt though. It seemed a lot harder to get the wrench to click on that bolt, then, I ran out of oomph on the fourth bolt and couldn't get it to click. It was then that it dawned on me that something wasn't right. I tried resetting the torque wrench but when I got it back to 0 ft-lbs, the handle just kept twisting. So I backed those two bolts off a bit. I ordered a new wrench and two new bolts, because I'm sure I stretched them too much. I'll try to get those in next weekend.

https://www.amazon.com/Performance-Tool-W83148-6-Piece-Disconnect/dp/B000N37D7W/ref=sr_1_15?ie=UTF8&qid=1474304246&sr=8-15&keywords=fuel+line+disconnect+tool

Here's the set of fuel line disconnect tools I have. They might not last forever, but this is the second time I've found myself wanting them in the last decade, so they work fine.

[Napalm]

don't worry about those bolts and if they aren't loose don't remove them. you didn't stretch them at all.

and I know, I know the whole but TTY . . . . . .

they are not torqued to yeild - or even near yield. for the size, material, and quality of the thread. sorry but they aren't. the whole set torque and angle spec is because the factory bolts have locktitie on them - it thus throws off a convential measured torque reading as it adds so much drag to the bolt threads. Just like how oiled bolts don't torque correctly either as they slip to easily.

so I suspect unless you cranked down on them with all your might - and I don't know if you are a power lifter using a 3 foot wrench - but I would say otherwise the bolts are just fine and I would leave them alone.

[J Wikoff]

Well... Want a pair of brand new bolts then? Lol.

I do lift, but my torque wrench is only 18".