Friday, the CEL lit up, P0191 and P2177.

I don't know that's it's related, but Thursday evening, I filled up with fuel. These gas prices are killing my budget, so I thought I'd try making my own 91 octane for my tuned SS.





This equals an E35 mix overall. It's not a flex fuel vehicle, but the new(ish) LHU engine and Opel fuel rail should be able to handle E85. I don't know about how any other parts will tolerate it.

I also recently was getting an occasional pending P0101, although it never hard set or lit the CEL.

I'll have to check, there might be freeze frame data.

https://www.obd-codes.com/p2177

https://www.obd-codes.com/p0191

It looks like the P0191 should be diagnosed first, but it is only in pending status.

 

They are related. From Mitchell OnDemand:

P0191.pdfP2177.pdf

 

There’s a big difference between your ethanol blend blend and 91 octane gasoline. The octane is surely 91 or better but the problem is with that ethanol in it you need more of it to get a proper a/f. Thus, a fuel trim complaint such as P2177 should be at least no surprise if not expected. Also, unless you’ve got big injectors you run the risk of a dangerously lean condition under power. I’m not sure there’s anything to diagnose with regard to the P2177. My inexpert opinion is the fuel blend is causing it. To use it you’d need to tune for it, and review whether you injectors are up to it. But if you did that, why not just go to an E47 tune?

I’m not saying it isn’t, but I don’t know how the fuel rail pressure sensor performance code, P0191, is related. Or the P0101.

 

I just edited my prior comment because I had P2177 and P0191 reversed.

 

 

Run to half tank and refill with the fuel required for your tune, then again to half tank , then full tank.

 

Thanks for the responses.

I'll do that, Oldblue. Here is the freeze frame for the P2177. The P0191 is pending. I've cleared the codes, we'll see what happens. Seems that the code set while at freeway speed, if that changes anything.

 

Keep your eyes on the road and your hands upon the wheel!
I would suggest siphoning out the fuel tank for your lawn mower, but these tanks don’t allow it!

 

The actual title of the P2177 test:

 

An update: since refueling with 91 octane (E10) a few times, the above codes have not returned. Thanks guys!