Good day,
I've been plagued with p1283 since last summer it would seem. The frequency of the code showing up has increased. I've tried smoke testing the exhaust from test pipes forward and the intake plenum and vacuum lines and could see no issues.
I've measured the Afr on both banks, and the drivers side does dip into lean, and tends to be .5-1 Afr measurement lower than bank 1.
I previously had my driver's side valve cover venting to atmosphere, but in an attempt to get rid of this code. I tried to block this off.
Once I did, the afrs balanced out and no more code. Now when I shut off my car, there is the sound of air escaping and pressure being released.
I have a feeling there shouldn't be pressure of any sort impacting the afrs coming from a valve cover. I've got some guesses in what this could, but they are only guesses.

*Edit* I meant to add this, I did install a check valve on the non PCV valve cover so it can breath out then vent to atmosphere, but not suck in. The afrs look good still, and no engine code. But when I turn off the car, it creates that hissing noise as if it's depressurizing.

*Edit 2*

So I figured out the error I made by blocking off the drivers side from pulling air in. It seeks the PCV system pulls from that side and it's pulled out on the passenger side PCV valve thru the intake plenum. So back to square 1 trying to figure out why I'm lean on bank 2.

​​​​​​Any insight and help is appreciated. Thanks!

 

You're going to blow gaskets out by plugging the PCV, it MUST BE VENTED either to the intake (emissions legal) or to the atmosphere (emissions illegal). Pressure (blowby gas) builds up in the crankcase from cylinder combustion chamber gas escaping past the rings. If you don't vent it off it builds up and blows out things like the valve cover gaskets, oil pan gaskets, etc.

 

First check fuel pressure, if it's fine you probably have a bad injector or the O2 sensor is bad.

Edit: you can usually tell by the spark plugs if an injector is clogged, one cylinder will look very lean on the plug.

 

Since the crankcase is being vented via valve covers, if one is blocked, wouldn't the venting then go thru the other banks valve cover since the crankcase is 1 chamber?
I did have my suspicions that this maybe an injector, I will check the plugs on the impacted bank.

 

Any tips on checking fuel pressure? I don't have a guage to test this. I do have uprev so I am able to do some basic logging and tracing.

 

Gauge is the only way, you need to add a sandwich adapter to the passenger side fuel damper, then you can either add a permanent gauge to the adapter or just use a fuel schrader valve.

https://www.z1motorsports.com/z1-pro...rt-p-9160.html