Hi All,

I have a 2001 Cherokee that threw a misfire code the other day.

First, a quick bit of history because it may be related. I removed the front bumper to put my wheels/tires from my old Cherokee on it. In the process, I had to remount the vacuum reservoir. It's now mounted to the diagonal crossbar right above the passenger side horn. It doesn't seem like the best place to put it and I'm not sure the vacuum line has a tight seal.

I mention the vacuum reservoir because, as I understand, it is used for the climate control. At the time the misfire happened, I had the A/C running and turned off the vehicle with the climate control **** still on A/C. When I came back to the car, I turned it back to normal vent (non-A/C) right before starting the car. It started really rough and almost stalled. I gave it a little throttle to see if it would clear up, turned it off and turned it back on. It's been running fine since then, but I've had the check engine light on. The engine code is saying a cylinder #1 and #2 misfire.

So my questions are:

1) Does this make any sense as to why it would have misfired that one time if the vacuum line isn't sealing to the reservoir properly?

2) Assuming the engine isn't misfiring (it doesn't seem to be except for that one incident), do I need to reset the error code or will it check it and see that it's not actually misfiring and turn the check engine light off?

Hopefully that's enough information, but let me know if there's anything else that would be helpful. Thanks in advance!

P.S. - If there's a better place to mount that vacuum reservoir, please let me know.

 

I was able to get the codes cleared (coworker happened to have an auto scanner with him). If anyone has insight as to why this might have happened though, I'd still love to hear any theories.

Thanks!

 

I don't see the relationship of a misfire to the work you did.

Get new NGK copper plugs in there, gapped to .035 if the codes return.

 

Alright, thanks tjwalker!