VS - Code 46 & 44 troubles..

[t0bes]

1996 VS V6
Part 1.
Car was running pretty bad, after reading all threads on economy lately I decided to try and improve things. Car was showing error codes 76 (air fuel ratio variation) and 44 (RH O2 lean).
- Replaced leads/plugs air/oil/fuel filter and 2 x new O2 sensors.
Code 76 hasn't come back.. yet.
After changing the above, CEL still came on, and when checking, Code 44 has remained and now also Code 46 (no reference signal while cranking). The car stalled on me too, seems to drive fine, but when approaching idle speed (i.e. slowing down for traffic lights) it starts to hunt/hesitate. So, for part 1 - why whould Code 44 (RH O2 lean) still exist?

Part 2.
With the above symptons I replaced the CAS, reset ecu, & STILL have Code 46! And the car is wanting to stall when dropping back to idle. It's like the new CAS has made the problem more obvious! Could it be the harmonic balancer(no obvious signs of cracking etc).. or something like the idle air control? What else would cause code 46 and more importantly the car to want to stall when dropping back to idle?

[delcowizzid]

try a spare dfi module under the coils

[The1]

could also be crank angle sensor

[chrisdoesitbetter]

could also be crank angle sensor

it cant be...he changed it

[chrisdoesitbetter]

so you ended up doing the CAS? lol i still think its a sensor... because the car seems to idle fine and seen as you have checked and changed almost everything. a few things to try

MAP (manifold absolute pressure) Sensor- monitors things like load and speed and adjust fuel, timing etc. accordingly. but i dont know if the VS use one of these.
Camshaft Sensor- the name says it all.

[t0bes]

Yep, replaced the CAS, still the same.. VS has a MAF, cleaned that this morning, no change.

Had a spare DFI module, swapped that, still the same.

Cleaned throttle body out still same, going to swap out the IAC this arvo and see how it goes.

Still got Code 44 / 46 and back again 76.

Would code 46 just be coming up because the car is stalling? i.e no real problem - fix the stalling/idle = fix code 46?

driving me nuts!

[chrisdoesitbetter]

na i meant a MAP sensor its a different thing but im not sure if the vs has one. mine had a loose connector and it ran very rich

[chrisdoesitbetter]

it should have a vac hose coming off the throttle body or inlet manifold

[The1]

Is it doing it when the engine is cold and hot or only when hot or cold?

you could also check for vacuum leaks just to be sure, check the vacuum solinoid on the back of the engine and the vacuum hoses on the throttlebody.

Code 44 says RH side is lean on fuel.

So i would first try swapping the o2 sensors over from the other side, if the code continues then you have a problem elsewhere like exhaust leak on the RH side or bad spark plugs or leads, fuel injectors clogged on RH side.

You could also have the ground loop issue, is your 02 sensors the 4 wire version with the heaters? Find the pin on the connector with 12volts and cut and tape the wire on the 02 sensor up.

[chrisdoesitbetter]

have you had troubles with your Powertrain Control Module. if its not related to any of the things above check it.

[Brett_jjj]

If you have replaced the sensors and the error code is still showing up, its either got to be the wiring or the ECU itself.

[kramer]

i'm having these problems too champ,

mine is spitting out error codes randomly and playing up stalling when going from drive to reverse ( vs v6 4 speed auto). it's not stalling at traffic lights anymore thankfully but mine is spitting out :

12, 13, 44, 63, 64, 65, 76.. no idea what the problem is and i've cleaned out throttle body, plenum, iac, new o2 sensors and ground loop fix...

no idea really mayby have to bump up the base idle, let us know if you figure it out though!

[Brett_jjj]

All these error codes point to a vacuum leak somewhere around the engine (inlet manifold) or vacuum hoses and vacuum reserve tank under the left front guard.Or behind the dash(heater controls).A guy I know had similar codes showing up,he'd replaced the oxy sensors etc.We went over everything looking for vacuum leaks etc,found nothing,so we changed the inlet manifold gaskets and no more error codes,so it was leaking somewhere,we didnt find where though.The gaskets were all still ok.Weird.It idled heaps smoother too.It idled rough as guts before the gaskets were changed.

[chrisdoesitbetter]

his car runs fine though...it just uses a bucket load of fuel, dumps unburnt fuel when he gasses it. checking for vacuum leaks and the inlet manifold seems logical though

[t0bes]

thanks for the suggestions guys..

wasn't able to swap the IAC out, as the spare wasn't worth putting in! Can't get a new one until tomorrow.

Problem happens hot or cold, yes I have the 4 wire sensors - I'll search that one first, rather not cut anything if I don't have too.
Worked out how to drive it now without stalling. And yep, leaning towards something vacuum related or wiring / ecu - will check all that out when fitting new IAC 2moro and post back.

see you tomorrow chris, if I make it!

[chrisdoesitbetter]

what do you do to stop it stalling? brake torque it? lol see ya tomoro

[t0bes]

Hopefully, my problems are solved. Will have to see over the next week how it goes, but it looks like the cause of all my problems was a faulty MAF - it wasn't working at all = ecu making the car run rich. (Code 76!!!) So, it looks like all the problems were because of this.
Can't really explain why one bank was running lean though? And after changing the MAF over I still got a code 44 again. Although it looks like I had bought a faulty O2 sensor, I was about to swap them from L to R and it rattled. So I'm running one of the 'old' ones + the one good new one.
No error codes so far, and fuel consumption appears to be good - it was an instant improvement after swapping the MAF. If all goes well, I'll probably pick up 2 more new O2 sensors, because there was about a week there where they were dumped on with fuel.
I have replaced the IAC ($66), and with this and the MAF the car hasn't wanted to stall and it's idling and running really smoothly...so far, fingers crossed.

[kramer]

i'm still keeping an eye on this thread hoping to fix the same problems when i'm back in aus... so please do keep on posting your findings!

[t0bes]

no probs - since last post I'm only on my 2nd tank of fuel, haven't been doing much driving with this lately. The 1st tank of fuel after afm fix I averaged 15.1L/100k, not fantastic but instant improvement and far better than the 20+L/100k it was drinking before. Exhaust is running a hell of a lot cleaner, rear bar is no longer covered in soot!
There was a period of about a week before the afm was changed were I had had just put plugs and o2 sensors in & it was still running quite rich. Because of this & I just haven't had time, but I want to put new plugs & 2 new o2 sensors just incase they were affected from that week of driving and see how it goes.
As for stalling, it hasn't yet and I don't think it looks like it wants to/or will..
Cheers.