GenVibe - Community for Pontiac Vibe Enthusiasts

We have owned this Vibe since summer; we're not the original owners. Since then we have had to take it in twice, for the following work (as determined by the auto shop): Diagnose cooling system (replace cooling fan motor, Cooling system service, engine hot oil service), and Diagnose no-start (Fuel pump remove and replace).

Those issues have clearly lifted, but about a month ago the car began to idle between 1000 and 1500 RPM, at least for 10 minutes whenever in neutral, but then it drops down. After that point, when in neutral the car sputters and sounds like it may stall out (though it never does). My wife has been keeping an eye on the fuel mileage and says it's horrible. Then, two weeks ago, the Check Engine Light came on.

It now has 142,000 km on it. We have been keeping up with oil changes. I borrowed a code reader and it threw out the P0171 System Running Too Lean code. I have cleaned the MAF sensor with some CRC cleaner and dumped some non-solvent fuel injector cleaner into the gas tank, but so far the issue is persisting. What shall I do next?

Those other repairs cost so much at the shop, and I can't afford to keep paying such high repair bills. I really need to be working on this issue before it gets worse.

Intake gasket would be my first suspect. Common failure on these cars, search it. Mine was done at the dealer before I got it.

My 2006 Matrix gasket went at 134,000km, very similar mileage and symptoms to you. It wasn't an expensive repair, ~$300 from Toyota dealer.

I agree with intake manifold gasket. Actually it could be any vacuum leak between the MAF sensor and the cylinder head. These leaks add air that does not get measured. As a result the computer calculates too little fuel.

The intake manifold gasket is the most likely culprit. I would also replace the throttle body gasket. It is not difficult to do this job yourself. See here: viewtopic.php?f=20&t=33056#p475654

What should my RPMs be when idling in my Vibe? I saw someone else write about their Matrix that it was idling at 500 and they could feel shaking through the steering wheel.

It should idle at 700 when warmed up.

Welcome to genvibe!

Here's a thread on this issue:

viewtopic.php?f=12&t=43828

A cold Vibe will idle around 1,900 rpm at start and drop gradually as it warms up. Circuitsmith is correct that operating temp idle is 700 rpm. I would add that you'll get +/- 10 rpm and you should read the tachometer at the bottom edge of the needle for the most accurate indication.

If you decide to do the gasket change yourself, your 2005 is either a FWD with drive-by-wire or an AWD with throttle cable. Not a huge difference in the difficulty, but make sure you have the correct instructions.

Good luck and let us know how it turns out!

I would add that you shouldn't read the tach at all for RPM (when diagnosing engine issues). Use a scan tool for accurate information.