So a couple of weeks ago I got a SES light for Low voltage on the O2 sensors. I have long tubes so I checked for a burnt wire on the O2 extensions. Yep. So I fixed the wire and the code goes away. Yesterday, which is 2 weeks later, SES light comes on again. I check the Codes and got 4 Codes.
Now, keep in mind the car is running great. I just put plugs in the car a week ago. I have new plug wires on it too. But the Code combination is what concerns me. Here is what I have:

P0171 Lean Code on Bank 1
P0174 Lean Code on Bank 2
And the killer
P0300 Random multiple misfire

So it could be O2's, fuel pump, Plugs, Wires, Coils, Injectors, Vacuum, Intake leak, TB gasket leak or god forbid low compression on a cylinder?

Where would you start?

I cleared the codes yesterday and after a few minutes the SES light came back on. I just checked the codes again and I got 1 set and 2 pending. P0174 is set and P0174 & P0171 are pending.

Long Term fuel trim is 25%

 

First and easiest thing to do is check the fuel pressure at the rail.

 

At lunch I went out and started at the PCV hose. The little hose that connects the PCV to the intake had a huge hole in it. So I replaced that and cleared the code. I haven't got to run it yet so I'm not sure if that'll fix it or not, but I plan to check the fuel pressure anyway since I spray the car. Just for giggles I'm putting a new fuel filter on it too since I don't know when it was changed before I bought the car 2 years ago.

 

That fixed it.

 

sweet