Code help h55 and h64

[Dafink]

So my car is throwing codes h55 and h64. It's riding rough around 3000 rpms and the power seems limited.

Anyone familiar with this problem?

[MuRCieLaGo]

We're two! See my thread here:

http://www.zr1.net/forum/showthread.php?t=26445

Keep me updated if you find something! Are your codes intermittent? What year is your ZR-1?

EDIT: I searched and I noticed yours is a 1991, just like mine.

Take also a look at this thread there:

http://www.corvetteforum.com/forums/...-and-64-a.html

Changing my o2 sensors is my next step.

[Dafink]

Seems like it's either the O2 sensor or ecm, leaning towards ecm since it feels like power mode is not getting selected. Does that make sense?

[MuRCieLaGo]

What do you mean by "power mode is not getting selected"? For your information, when you got a SES light, you can't enable "Full engine power".

[Dafink]

I think if there is an issue with the ecm it can result in the power mode being "unselectable"

Interestingly I drove it again this morning and it seemed to run fine, now I'm wondering how far to push it before diving in deeper.

[bdw18_123]

If the check engine light is on, the ECM won't let full power mode turn on, even if the code is not related to the secondary system.

[Dafink]

Swapped out the injectors and all is good now....!

[32valvesftw]

For future reference, the GM Service Technology Group Fuel and Emissions Course handbook, states that Code 55 is "Fuel Lean Monitor" It gives 3 possible causes
1. Secondary ignition insulation fault
2. Lean Injector
3. Inlet filter restriction to injector.

Code 64 is "right Oxygen Sensor signal-lean"
It gives several causes one of which is injector restriction - right bank

So it looks to me like you nailed it by changing out the offending injector. Good work.