stock 2011 misfiring , bad fuel?

[BLK93GT]

I've been having issues a few days after getting some ethanol free 91 octane. The car is misfiring, #5 and #6 plus random. I noticed last night my fuel pressure drops under load and AF goes lean as well. Trying to avoid the dealer. It has pedestrian warranty but I hate dealers. I added dry gas but no change. Plugs look fine but smell strange. Car is running warmer than normal as well.

 

[barspen]

Might want to change the fuel filter if you haven't done so yet. Also, not sure if dirty MAF could cause this, but might want to pull in and clean it off. Good luck!

 

[ZeroSVT]

Like said before, fuel filter could be an issue.

Can you log you fuel pump duty cycle? It may be a failing pump since the pressure is dropping.

I would not run it hard anymore until this issue is figured out, especially if its running lean.

Cheers,
-Matt

 

[nxhappy]

any codes? Could be a coil on plug, or fuel problem as others have stated.

 

[BLK93GT]

Misfire on 5,6, and 7 is pending. I'm going to hook it up to my Autoenginuity program later and see what else pops up. I am going to get a filter and do that along with some new plugs.

 

[scotsam]

Might be a dumb question but did you clean and/or power wash your motor lately?

 

[BLK93GT]

Might be a dumb question but did you clean and/or power wash your motor lately?

No not in a while and I always l blow the engine bay out. When I pulled 2 coils it's was totally dry and plugs looked good.

 

[Alldaylong]

What ended up fixing the issue because I'm having issues with my car running lean at WOT, but it runs fine driving easy around town. I'm thinking my fuel pump is failing.

 

[BLK93GT]

What ended up fixing the issue because I'm having issues with my car running lean at WOT, but it runs fine driving easy around town. I'm thinking my fuel pump is failing.

The driver catalytic converter was broken, I noticed when I was logging data that something was up and brought it to the dealer. New hpipe under warranty and it was back to better than new!

 

[RedVenom48]

Was it setting any cat efficiency codes?