What does the fault code mean ?

[Mikee5]

Hi guys,

I have recently purchased a 2009 X5 E70 4.8i.
The Check Engine Light has since come on with error codes
29f4 & 2D32.
I looked them up and found their "definitions", then did some searching on google and this forum, which led me to believe I had a vacuum leak (2D32)which was probably causing the car to run rich and fouling a catalytic converter (29f4).
I went searching for leaks and found tube from the MAF to the Throttle body was incorrectly attached and leaking and that the CCV assembly had been butchered by a ham fisted repairer in the past, and was passing engine oil into the inlet manifold, which was then blowing out as smoke in the exhaust
probably further fouling the cats.
I have ordered a new CCV assembly and a new inlet tube, both are currently sealed up with silicon sealant till their replacement are installed. CCV is working sort of.
I cleared the codes and took the car for a drive and the error lights stayed off. All of this leads me to my questions:-
1) How often does the car look for error codes, as the CEL has not come back on and
2) What does "Error not currently present" mean? I rescanned the car both codes came back, 29F4 is there as a current fault, I expected it to be there at least till the oil clears out. 2D32 shows not as a current fault but as " not currently present" is it just a historical listing or something else?

Any help would be appreciated,

Thanks
Mike

[Mikee5]

Ok, the new CCV assembly arrived and was fitted by me.
Everything was sealed and working properly; I cleared the codes again and then drove to my daughters home in Gympie Queensland (about 1200K's) from where I live.

About half way up the CEL came back on, this time it was only the 29f4. I cleared the code again, finished the trip up and drove around for the next 8 days with no CEL and no smoke.

Yesterday, I left to come home, started the car and the CEL was back.
I continued to drive home, the car drove flawlessly, no smoke, lots of power, at full throttle it runs cleanly to its 6500rpm shift points and good fuel consumption.

When I say no smoke, the car has always started without any smoke but before I replaced the CCV assembly it would start to blow oil smoke after 10 or 15 minutes of idling when hot. After I replaced the CCV assembly this gradually reduced and I did'nt notice it at all when in Gympie. Also the exhaust pipes had a sooty black look and texture before the trip, but once at Gympie they were largely clear.

As for fuel economy, going up I was pulling a loaded trailer and the rear seats were folded down with more cargo, all in all about 1.5 tonnes of extra weight. I averaged 15.8 mpg for the trip up, traveling at the legal speed limits. Coming back the car averaged 26 mpg. I did'nt check the fuel consumption while travelling around Queensland, but it seemed pretty good.

All of this leads me to think that there is nothing wrong with the engine or cats but that one of the o2 sensors is crook, but i don't know which one. I have after arriving home since cleared the code again, but would like a permanent fix.

I assume 29f4 refers to a specific o2 sensor, but which one?
Also is there a way to test the sensor before I replace it ?

The car is due for a registration inspection in May and I would like it to not only pass but actually be ok.

Any help or advice would be greatly appreciated.

Mike

[ard]

29f4 is a catalytic conversion efficiency code. Not, necessarily an O2 sensor bad code.


Keep in mind that O2 sensors are a maintenance item. If they are suspect, I tend to replace. Pre-cat. Less of an issue w post cat sensors, they see far less abuse. Id replace both precats



There are some good youtubes on diagnosing these- looking at the actual O2 sensor readings to try and discern whats up. A way to 'test' them.



Ya get over to great sandy at all? Good times there years ago.

And for others, 'crook' is aussie for 'gone bad'.

[Mikee5]

No, i was too busy being free labour for my daughter in her move to Queensland, I'm glad to be home so I can go back to work and have a rest.