Hey fellas, having some issues and I was hoping to get some feedback on. I have recently been having these codes pop up and I’m stumped. P1174, P1300, P0308, P0304 and P0302 have appeared and from what I can tell it’s something to do with passenger side bank. The pcv is good and all associated hoses were recently replaced. I’m currently replacing the valve cover gaskets per usual oil leaks, anything else you guys recommend?

 

You are correct that the problem has something to do with the passenger-side bank of cylinders. If not for the P1174 code, which indicates a vacuum leak, I would suggest replacing the upstream O2 sensor on that side. It's somewhat unusual to have a vac leak on one side only.

A well-known method to identify where a vacuum leak is occurring is to perform a smoke test. You can do this yourself with a cigar and a length of tubing attached to the port below where the brake servo vac line connects to the upper intake. That port should have a small silicone cap on it. Just remove the cap, connect a hose to the port, fire up the stogie and blow smoke into the intake via the hose. Then look to see where the smoke comes out. And oh yeah, first remove the intake tube from the throttle body and cover the opening with a balloon or rubber glove or something similar.

My guess is it's one or more leaking fuel injector O-rings on Bank 2. Good luck.

 

If used improperly, every machine is a smoke machine.

 

I don't know whether or not eitydeuce got this sorted out, but in replying to another thread today I was reminded that a failed upstream O2 sensor can trigger a lean code (P0171 or P0174) on just one cylinder bank.

I know it's a PITA, but you could try swapping O2 sensors side-to-side and see if the P0174 moves and becomes a P0171. Or, you could try the smoke test I describe earlier and if that does not yield results then try swapping the O2 sensor.

You could also go ahead and replace the O2 sensor without swapping it, but my mantra is diagnose, diagnose, diagnose.

 

Actually it was a leaking injector O-ring, I replaced them not too long ago with OEM o-rings but they still managed to get brittle. I replaced all of them again and hasn’t given me a code yet.

 

Great! How did you determine the problem was a leaking injector O-ring? Did you do a smoke test?

 

I built a homemade smoke machine and adapted it to fit the intake right after the maf sensor, shortly after it was clearly billowing out of the #2 injector on the intake side. The o-rings on the fuel rail were fine however almost all of the rings on the intake were hard and compressed. I replaced them no more than 3 years ago when I replaced my head gasket’s.