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Engine stumbles at take-off, please help!

Posted By: Nukeiridium

Engine stumbles at take-off, please help! - 04/28/17 10:19 PM

Hi all! Long time no see! laugh

So my Sporty has about 160K miles now. It has been good, but recently is having a problem.

When I hit the gas off the line, the engine will sometimes stumble and sputter, like it's missing or something. It seems to always do this at low throttle levels. It happens in any gear, not just off the line. The common thread seems to be when I'm giving it a little throttle. Once the engine revs up to higher RPMS and I open up the throttle more, the issue seems to go away.

I thought maybe I had a bad coil, so I replaced all the coils and plugs. Problem still there.

I have 2 check engine light codes, one for the O2 sensor bank 1 signal out of range, and one for knock sensor 1 signal out of range. I'm worried this is some kind of strange electrical problem.

Any ideas? Anybody seen a similar problem?

Sometimes starting from a dead stop, the sporty will shudder and shake forward and back until the engine finally revs up and stabilizes.

Sometimes it doesn't do it at all! It seems to depend on something, like temperature, or the phase of the moon or something. I'll have days where it doesn't happen at all. Crazy thing!

I checked the battery connections and they are tight btw. Kinda seems like something might be loose though somewhere.
Posted By: 4x4Wire

Re: Engine stumbles at take-off, please help! - 04/29/17 01:19 AM

Clearing the faults causing the check engine codes is the first step.

One or both sensors are bad....
Posted By: Nukeiridium

Re: Engine stumbles at take-off, please help! - 05/04/17 10:56 PM

I'm gonna replace both sensors this weekend. Wish me luck... I sure hope it's really the sensors that are bad, and not a problem with the wire harness!
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