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Hi everyone. 2009 Pontiac Vibe GT (Matrix) Toyota 2az fe 2.4l engine, 183k miles. Recently rebuilt engine/new catalytic converter. As the title says, my LTFT gradually gets up to just over +10 at idle after about an hour of driving. Trims adjust to about +2% with continuous driving, then increase again at idle.I can't find any vacuum leaks (doesn't mean there aren't any). Upstream 02 sensor is new, but downstream is original. Car runs great at first, but fuel trim and idle gradually increase over time. I do a lot of idling/stop and go driving. Is + 10.9% acceptable for a 13 year old Toyota engine, or should I try to diagnose a problem? Any ideas? Thanks!
Eh, it's right in the boarder line. I'd look into it myself, only because it would bother me knowing it's there.
If it's warmed up, do the numbers get better just by giving it some rpms? I believe that's what you are saying here, which would indicate a vacuum leak.
What have you done to look for leaks? Smoke test, propane/spray and watch trims/o2, water?
Remember to pinch off the brake booster and purge valve too, which can hide leaks.
I had one of these once and was confident I had a leak but no smoke was showing up and I couldn't find it. I just ended up crossing my fingers on it being the intake, and it was.
In my case it was a hunch that ended up being right that I only found after I replaced the gasket. Best to avoid bunches when possible though, ha.
How exactly have you checked for vacuum leaks so far? A smoke test would be ideal, but you can also use unlit propane in suspected areas while monitoring stft. If you hit a leak the value will dive because it's sucking in the alt fuel. You can do the same with something like brake cleaner too, but it's less safe.
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