GenVibe - Community for Pontiac Vibe Enthusiasts

I have a 2003 vibe. Only in cold weather when its below 25 degrees it will have a rough idle and the check engine light comes on. I have a P0300 code. Ive already changed out spark plugs and coils. I purchased a new gas cap and put heet in on almost empty and refilled. It also does this when the weather goes from warm to a drastic cold. I live on cleveland and the weather gets pretty crazy here. Also its only i startups. Anyone else have this issue? What did you do to resolve it?
Thanks,
Greg

Also it has 150k miles.

Welcome to genvibe!

Forum search is your friend!

Try this thread for some helpful thoughts: viewtopic.php?f=11&t=46285&hilit=P0300#p520322

Also, this PDF shows a list of possibilities: http://forums.genvibe.com/files/importe ... ip0300.pdf

Assuming a stock air intake, I'd clean the MAF sensor if that hasn't been done in a while and check the vacuum hoses for leaks and good connections.

Most likely you have a vacuum leak. The intake manifold gasket is suspect. It gets drenched from oil that comes in through the crank case ventilation system and goes out of shape.

is it just me or have others noticed that when our cars (or any car for that matter) is parked on an uphill slope with the gas tank facing downhill, that we often get a studdered start to our car? I used to think it was a matter of moist nights affecting the wiring in the engine. I'm now thinking that the gas is flowing back into the tank and causing a "fluttered" start. It only happens occasionally, but at each house I've lived since owning the Vibe, the front is elevated when parked. Thoughts?

Mine did this once the other week, I had a P0301 code and replaced the downstream 02 sensor, the fault has not come back. My intake gaskets have never been replaced in 259000 miles. Running wise it is as strong as ever.

Caretaker wrote:is it just me or have others noticed that when our cars (or any car for that matter) is parked on an uphill slope with the gas tank facing downhill, that we often get a studdered start to our car? I used to think it was a matter of moist nights affecting the wiring in the engine. I'm now thinking that the gas is flowing back into the tank and causing a "fluttered" start. It only happens occasionally, but at each house I've lived since owning the Vibe, the front is elevated when parked. Thoughts?

I never noticed that, but that's because i park downhill. What I did notice though is that it starts quicker with the tank full vs 1/4 and less.

But why only in cold weather? You would think that if something was wrong the check engine light would go off all the time.

thatvibeguy89 wrote:But why only in cold weather? You would think that if something was wrong the check engine light would go off all the time.

I'd start by replace the intake gasket. Only get the updated orange gasket from Toyota. It shouldn't cost you more than $20 and is relatively easy to do. I've done it on two different 1ZZ cars now.

I'll link you to a post on Toyota Nationhttp://www.toyotanation.com/forum/132-c ... -pics.html, which was also linked from this post here on GenVibe: viewtopic.php?t=43828.

It explains the replacement procedure and gives you the part number. I've found it easier to go to the parts counter with a part number, instead of going to counter and saying I need a part for a "Matrix". There's fewer questions. There's also a link in the first post which will take you to a Toyota TSB PDF that lists a P0300 as a possible code from a bad intake gasket in cold temps. I've attached a screen shot from it.

thatvibeguy89 wrote:But why only in cold weather? You would think that if something was wrong the check engine light would go off all the time.

I can see two potential reasons: when it's really cold the rubber seal shrinks more and gets really stiff. Therefore it lets more air through.
2nd, really cold air is really dense which adds to the leanness of the mixture.

Coolharts wrote:Mine did this once the other week, I had a P0301 code and replaced the downstream 02 sensor, the fault has not come back. My intake gaskets have never been replaced in 259000 miles. Running wise it is as strong as ever.

What was the temperature outside when the engine light came on?

I should also add that the exhaust from the front end of the car is a little noisy. That could be the bad gasket? Because if it was an o2 sensor or a dirty MAF sensor it probably wouldn't be making this noise?

thatvibeguy89 wrote:I should also add that the exhaust from the front end of the car is a little noisy. That could be the bad gasket? Because if it was an o2 sensor or a dirty MAF sensor it probably wouldn't be making this noise?

If that leak is in front of the O2 sensors then it definitely can throw them off.

Have you tried to replace the intake gasket, yet? Its cheap and pretty easy to do and I have already proved to you by posting a Toyota TSB that it can be responsible for code you received in the circumstances you described. I'd start there. I even posted a link to instructions to walk you through it.

If you're concerned about an exhaust leak, then you could take your car to an exhaust shop to have them check it out for you. If there is an exhaust leak before the downstream O2 sensor, then yes, it will most likely throw a code. However, I don't think it would be a P0300. I would expect to see a P0420 (cat efficiency code). If you're hearing exhaust louder in the front, are you sure you're not hearing the intake or some sort of vacuum leak? Maybe take a video and share it with us to help pinpoint the sound.

I had this issue myself. First I changed the intake manifold gasket but the problem persisted. Cleaning the IAC valve solved the problem. However i wasnt throwing any codes.

I Reused the o-ring by the way and no issues.

viewtopic.php?f=17&t=36489&p=476353&hilit=iac#p476353

Replacing the gasket is super easy, definitely worth the $15 for the gaskets and an hours time. My idle is much better and the throttle body is clean. Cleaned the original PCV and reinstalled.

Final culprit was I had bad battery wires. Plus the purge valve wasn't working. It runs a lot better now.

thatvibeguy89 wrote:Final culprit was I had bad battery wires. Plus the purge valve wasn't working. It runs a lot better now.

Thanks for the feedback! I am glad for you it was fairly simple in the end.