Anyone Had A P0174

[cc mac]

The system too lean bank 2 fault code comes up intermittently, does anyone out there have any experience regarding this?

[paolo137]

Sadly, I do.

Unfortunately, that code may be triggered by a long list of causes.

There's a number of quite simple checks you have to perform. If they don't work, you're out for big troubles.

If you get the code on one of the banks only, though, it might be easier to pin down the problem.

1) Check the fuel cap: if it does not close tightly, you'll get lean mixture

2) Check all the hoses related to the engine air recycling for loose ends or punctures (same reason)

3) Clean the MAF sensor

4) Clean the PCV valve (over the head of the engine)

5) Clean the IACV valve

6) Check the spark plugs and their wiring (change the spark plugs if they're old)

If none of the above works, you'll have to change the MAF and/or the O2 sensors (sure enough they're not ALL faulty, but it's unlikely your mechanic will try to change them one by one and put back the good ones).

Other than that, you have only the fuel injectors, or the fuel pump.

As I said, if you keep getting the alarm from one bank only, it might be one spark plug on that bank, or its wiring, or a fuel injector rather than a faulty sensor.

Please notice that I'm no mechanic: I just spent the last weeks scanning the web for this problem! :winky:

[cc mac]

I really appreciate your help with all of that info. Cheers.