Some codes I'm receiving in 01' 3.0 5spd
 

Ok so I'm getting the P0141 oxygen sensor code quite often now. It seems to happen if the let the truck idle too long. How do I tell which sensor to replace iirc it system 1 bank 2
Now some others are p0171, 0174, 1349. Once I clear them truck runs fine. I usually clear them on the fly.

My main question is if j replace the o2 sensor should this resolve all problems. Now I also know the battery plays a huge role in these trucks and probability on that ?


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The code P0141 means that there is a problem with the heater element circuit of the heated oxygen sensor. The control module monitors how long it take the sensor to warm up and start sending an adequate signal. The code is triggered when the sensor is taking too long to warm up. Water getting inside the heated oxygen sensor connector can caused the heated oxygen sensor fuse to blow. Before replacing the sensor, check for the condition of the heated oxygen sensor fuse and connectors. If the sensor and connector are OK, replacing the O2 Sensor 1 usually takes care of the problem

P1349 is an engine misfire code and normally have a fuel shut off.

P0171 and P0174 are lean mixture codes which could cause an engine misfire.

There are plenty of write ups on the P0171 and P0174 codes on this forum. I suggest you do a search.

Thank you


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With the misfire codes I would look into replacing spark plugs if those are originals, the lean running and misfire could ALSO be a ripped intake elbow boot, i'm sure you must have heard of the known problem with the M54, its an E46 problem too.

The intake boot is 15 bucks from dealer and OEM NGK plugs are 40 dollars, after you fix your O2 sensor issue I'd look into those two.

I have this same problem. On my X, which coincidentally (or not) is also an '01 5-speed 3.0, it's intermittent. Some days I have no codes and the CEL stays off for long periods of time. Some days I get one or two codes for O2 sensor heater circuit (usually bank 2) and it drives fine. Yesterday the light was off, then I was sitting at a stop light and it started to idle rough, and the CEL came on immediately. I pulled over, scanned it, and it came back with three codes for O2 sensor (one that said no input detected from O2 sensor), and two misfire codes. Turned it off, started it back up, light was still on but it ran fine. Light went off while driving to work today :dunno: I assume one or both sensors need to be replaced, but it doesn't make sense to me that sometimes they would work and sometimes it acts as if there's a complete failure? Worth noting, I replaced the intake book right after I bought it. Not sure about plugs but I'll check next time I'm under the hood.

This is interesting because now that I think about it, the codes seem to come up when it's really humid outside or when it rains. So there might just be a fuse I need to replace?

P.S. - I just re-read the first post and noticed that bit about the battery. I just replaced mine because there were a couple mornings where I had to jump start it, even though the battery was barely a year old. Could a battery really cause an issue like this?

The light came back on and it's running even worse, so I'm going to look at fixing it this week. I have the following codes:

P0161 - O2 Sensor Heater Circuit, Bank 2 Sensor 2
P0135 - O2 Sensor Heater Circuit, Bank 1 Sensor 1
P1345 - Misfire with Fuel Cutoff, Cylinder 2

The one about "no output from O2 sensor" is gone. Can anyone link me to a good resource for troubleshooting O2 sensors? I've seen some resources but nothing specific to the X5 / M54.

Also, since the codes describe a fault in the heater circuit and not the sensor itself, can I assume that buying new sensors won't necessarily be the fix? Or is the "heater circuit" all built into the sensor? Could it be something else that's the problem? Clogged cat, faulty DME?

Heater circuit is built into the 02 sensor, so buying a new 02 sensor will get you a new heater circuit.

As upallnight said, there were plenty of threads on these codes... before venturing into the oxy sensors, you need to find oout why you are getting misfires - this applies to both fellows with the problem... the DME will shut off the fuel to the problem cylinder to avoid FURTHER damage to the o2 sensors but, first, the damage may have already happened, and second, if you do not rectify the problem up the stream, your new sensors may get damaged too... and the cats don't like fuel coming down either, and the misfires can cause that happen...

check the reason for misfires... switch the coils on the question cylinder, see if the problem follows... pull spark plug (if plug is old or questionable, consider replacing all, as a maintenance item), switch to another location...

obviously, check for vac leaks, start with air filter, move to MAF, check the boot, check the throttle flap, clean if needed... check for vac leaks around the engine...

while a battery may cause a multitude of totally unexpected behavior, chances are it is not reason for misfire - unless we also alternator issues, that spikes voltage...

in other words, what i am trying to say, do some basic troubleshooting before starting throwing parts at the problem...

All the above. I would place a bet, that the DISA valve is also bad and sucking air. My kids drove the snot out of my 2003 x5 3.0 5-sp. since 2008. I finally made it my daily driver. Multiple codes.............. Positive smoke test. bad idle O2 codes, etc.
Replaced plugs, started using non ethanol fuel, repaired the DISA valve, replaced the Post cats. O2 sensors. and Voila. all codes were gone. She runs like a top. My 2 cents.

I had similar problems with my 01' X5 3.0 auto when it had 162K miles on it. It turned out to need a new Disa valve, plugs and all O2 sensors replaced. Checked all the coils with OHM and they were perfect. It now has 178K and returns perfectly smooth acceleration and amazing 21-22mpg highway. This site was amazingly helpful in diagnosing and fixing the problems. I also had assist with a local shop in Springfield,OR. BTW, I drove the car cross country last winter after the repairs.
Minus new BM trouble U issues the engine systems are flawless.