wat causes a code 42 in a vn v6?

[jaz 49]

hi, ive got a vn v6, now it has had this problem it comes and goes but i want to fix it proply. its pretty much a stock engine, except for its dual fuel, i dont switch bewtween gas and petrol with the battery connected as this seamed to set the error, but for no apparent reason the code comes up, wherather or not havin the gas effects things im not to sure. im thinkin it could be somethin is worn and is stuffed.....? any help will be appricated,

[madsav]

Sounds like it has somthing to do with the gas, pretty sure code 42 says its running rich? correct me if im wrong but pretty sure it has somthing to do with the o2 sencor

[W84N01]

lol, i have a 1989 VN sedan on straight gas. My error codes come up for the gas all the time for the O2 sensors.

The sensors can't detect the correct amount of fuel / oxygen thru the pipes, so they come up with an error.

I've replaced mine that many times, and it makes no difference. Just an expensive excersize really. If you're always on gas the problem will always come up, and there is nothing you can do, unless you can get that specific code taken out of the computer, and if you can figure out how to do that, please let me know.

But if you run the fuel and the codes still come up, i'd suggest you at least replace the sensor and if it still comes up, i guarantee you it'll be because of the gas.

No big deal really, i've never had a real problem other than the sensors not working.

[Cheap6]

Code 42 is an ignition system/ECM fault. It relates to the changeover of control over ignition timing between the DFI module and ECM. I have posted before on it = search may help.

Quick checks are:

Wiggle the wiring connectors at the DFI module and at the ECM, to check for a poor connection in the wiring terminal connectors.

Tap (not beat on) the ECM while the car is running and see if the code sets (Check Engine Light comes on). This is indicative of a bad connection inside the ECM. (The ECM is to the left of the passenger's feet.)

Unfixable O2 sensor codes, 44,45, on LPG are because the air:fuel mixtures, and therefore O2 sensor voltages, don't switch across rich to lean and back as fast as the ECM expects (in comparison to parameters based on operation on petrol) while running on LPG. An LPG (dual fuel) MemCal will ignore the O2 sensor codes when on LPG if you want a fix. There can also be global mixture errors, away from stoichiometric.

[jaz 49]

thanks for that guys, ive checked the connections at the ecm and no errors set, i changed the oxygen sensor a few months ago so that should be fine, the error comes on randomly so could it be a damaged wire bewtween the controls and sensors? i havnt run car on gas for a over a month and reset the computer after i changed them over. so if thers no problem with connections, faults in any wires or gas system involved, could there be a problem with my ecm or dfi module?