GenVibe - Community for Pontiac Vibe Enthusiasts

I have a 2005 pontiac vibe 2wd base with about 94k miles. I was recently throwing a p0420 code and replaced that cat and that seemed to solve the issue. I also replaced the spark plugs with NGKs and the ignition coils. This last week I have noticed my vibe sputtering randomly while idling with my foot on the brake. It is like a slighr decrease in the rpms. Today it actuallt started to sputter while driving at lower rpms. I am not getting a check engine light and my vibe seems to otherwise run smoothly. No loss of power just decreased gas mileage. I was wondering if anyone could help or has ideas. Fuel filter? Pump?

There is a good chance of a vacuum leak, in particular the intake manifold gasket. It takes a while until a CEL pops up.

Okay, I'll do some research. I am going to clean mass airflow sensor tomorrow and replace cabin filter and see what happens.

Let's start with the obvious. You state that your car's computer was throwing a code. Were there sputtering symptoms before the code came on or did the check engine light simply come on and you began to throw parts into it? If the latter, I would think the sputtering has something to do with the spark plugs or the ignition coils you put in. First, you should have gone with Denso products. NGK iridium should be fine too, but if your ignition coils are a "bargain brand" it is VERY likely that they are the cause of your sputtering.

There were no sputtering symptoms during the code. I used ngk iridiums. The check again light came on months ago. Had the code read. Changed 02 sensors. I did not just start "throwing parts in." The vehicle started to stutter prior to installing ignition coils and spark plugs. It seemed to subside after replacing coils and then it has slowly came back.

again, what brand of ignition coil did you use? Many mechanics have told me that if you don't go with Denso in Honda and Toyota engines, you are asking for a mechanical breakdown. In their opinion, nothing else seems to last very long and is a waste of money.

This is the same car from this post?
viewtopic.php?f=17&p=517037&sid=38dccd6 ... 95#p517037

Denso ignition coils.

Yes. Same car.

Cleaned the MAF sensor today seemed to help actually.
Also was able to pinpoint that the sputtering only occured when using the defroster. I will report back if anything changes.

the sputtering only occured when using the defroster

The defroster turns on the air conditioning. Consider getting the AC checked and if needed have it evacuated and recharged.

Must have been a coincidence. Went out for a little drive and it sputtered without the defroster on. I am going to put the old spark plugs back in and seem what happens. I have some Denso iridiums to try as well if that doesn't work.

With the other post of your oil problem on this car could it be a VVT system random malfunction problem? The lack of any codes does not help so the problem will take a lot of diagnostic time at this point. Until the problem gets worse and start throwing codes, it is just a guessing game over the internet. Some other guesses are: a bad fuel injector, crankshaft position sensor, VVT system not working correctly, temp sensor, coolant level or air in cooling system, cylinder compression, when was the last time the valve clearance was checked? A place to start is to check the fuel trim by reading the freeze frame data from a OBD II scan tool. You need to capture data when the sputtering occurs. Next move on to the coils and the crank and camshaft position data from freeze frame when problem occurs.

Thanks for all the help guys. I solved the problem today. I pulled out my new spark plugs and double checked each one. 2nd cylinder plug had a slight cracked in the ceramic. Replaced all 4 with denso iridiums. Vibe is running like a champ. Sputter is gone.

For spark plugs, you may want to invest in one of these:

https://www.amazon.com/Sunex-884505-8-I ... B0074HNK9A

It will help prevent cracking a plug as it is one piece, so no flexing down in the spark plug well that you would get with a regular socket and extension. Use dielectric grease on coil boots to keep them from sticking to the spark plugs and to seal coils and spark plug from moisture.

Thanks. Yeah i do attribute it to the crappy socket I had. It had a rubber seal that would always get stuck on the plug. I invested in a magnetic socket that is much better.